Merge pull request 'SLICE-6: export & the round-trip lock — canonical serializer + streamed export (SD-0002 §7.2)' (#29) from worktree-slice-6-export-roundtrip into main

A stored variant position is a CatalogVariant attribute, not a fields{} entry,
so the serializer emitted an empty Variant Position cell — which re-imports as
'reset to file order'. A non-sequential stored position (a merchant can import
explicit positions) then round-tripped to a spurious update, violating INV-12.
Emit str(variant.position) explicitly (like _write_image). The property-test
generator now assigns non-sequential positions to lock the regression, plus a
targeted test. Also wires isExportEnabled into ProductsPage (was dead code).
Both caught by the final code review.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

VERSION

@@ -1 +1 @@
-0.4.0
+0.6.0

backend/app/domains/products/__init__.py

@@ -0,0 +1,43 @@
+"""products domain — catalog + bulk CSV import/export (SD-0002 §6.2).
+
+Owns the canonical row model, codec, validation, diff engine, and import
+drafts/runs. Storefront-scoped throughout (INV-14); upsert is the only mutation
+(INV-10). Imported via this package surface only.
+"""
+from __future__ import annotations
+
+from pathlib import Path
+
+from .errors import (
+    DraftExpired,
+    DraftNotFound,
+    EmptyCatalog,
+    FileRejected,
+    NothingToApply,
+    PreviewStale,
+    ProductsError,
+    RunNotFound,
+)
+from .models import MAX_DATA_ROWS, MAX_FILE_BYTES
+from .service import (
+    confirm_draft,
+    discard_draft,
+    export_catalog,
+    get_draft,
+    get_draft_records,
+    get_run,
+    import_validate,
+    list_runs,
+    summary,
+)
+
+# DOC-3: the downloadable worked-example CSV the BFF serves at /api/products/sample.csv.
+SAMPLE_CSV_PATH = Path(__file__).parent / "sample.csv"
+
+__all__ = [
+    "ProductsError", "FileRejected", "DraftNotFound", "DraftExpired",
+    "PreviewStale", "NothingToApply", "RunNotFound", "EmptyCatalog",
+    "MAX_DATA_ROWS", "MAX_FILE_BYTES", "SAMPLE_CSV_PATH",
+    "import_validate", "get_draft", "get_draft_records", "discard_draft",
+    "confirm_draft", "list_runs", "get_run", "summary", "export_catalog",
+]

backend/app/domains/products/codec.py

@@ -0,0 +1,65 @@
+"""CSV codec — bytes → ParsedFile (SD-0002 §6.5.1). File-level gates only (PUC-5a);
+row semantics live in validate.py. Dialect detection is the INV-17 seam (SLICE-8
+adds Shopify)."""
+from __future__ import annotations
+
+import csv
+import io
+
+from .errors import FileRejected
+from .models import KNOWN_COLUMNS, MAX_DATA_ROWS, MAX_FILE_BYTES, ParsedFile, Row
+
+_REQUIRED_HEADER_COLUMNS = ("Handle", "Title")
+
+
+def detect_dialect(header: list[str]) -> str:
+    """The INV-17 seam: SLICE-8 recognizes Shopify's exact header set here."""
+    return "canonical"
+
+
+def parse_csv(data: bytes) -> ParsedFile:
+    if len(data) > MAX_FILE_BYTES:
+        raise FileRejected("file_too_large", "This file is larger than 10 MB.")
+    try:
+        text = data.decode("utf-8-sig")
+    except UnicodeDecodeError:
+        raise FileRejected("not_csv", "This file isn't readable as CSV.") from None
+    reader = csv.reader(io.StringIO(text))
+    try:
+        try:
+            raw_header = next(reader)
+        except StopIteration:
+            raise FileRejected("not_csv", "This file isn't readable as CSV.") from None
+        header = [h.strip() for h in raw_header]
+        for col in _REQUIRED_HEADER_COLUMNS:
+            if col not in header:
+                raise FileRejected(
+                    "missing_required_column",
+                    f"This file is missing the required column '{col}'.",
+                )
+        # First occurrence of a duplicated column wins.
+        col_index: dict[str, int] = {}
+        for i, name in enumerate(header):
+            if name and name not in col_index:
+                col_index[name] = i
+        known_present = [c for c in col_index if c in KNOWN_COLUMNS]
+        unknown = [c for c in col_index if c not in KNOWN_COLUMNS]
+        rows: list[Row] = []
+        for raw in reader:
+            if not any(cell.strip() for cell in raw):
+                continue
+            if len(rows) >= MAX_DATA_ROWS:
+                raise FileRejected(
+                    "too_many_rows",
+                    f"This file has more than {MAX_DATA_ROWS:,} rows — split it and import in parts.",
+                )
+            cells = {
+                c: (raw[col_index[c]].strip() if col_index[c] < len(raw) else "")
+                for c in known_present
+            }
+            rows.append(Row(line_number=reader.line_num, cells=cells))
+    except csv.Error:
+        raise FileRejected("not_csv", "This file isn't readable as CSV.") from None
+    return ParsedFile(
+        dialect=detect_dialect(header), header=header, unknown_columns=unknown, rows=rows
+    )

backend/app/domains/products/diff.py

@@ -0,0 +1,322 @@
+"""Diff engine — catalog × canonical products → apply plan + preview records (SD-0002 §6.5.2).
+
+Classifies each canonical product against the storefront's current catalog as
+add / update / unchanged / error. One walk produces two views of the same
+computation: a typed apply *plan* carrying resolved native values (Decimal etc.)
+for the confirm transaction, and JSON-ready preview records derived from that
+walk (stored as draft JSONB, served verbatim to the SPA) — so what confirm
+applies is exactly what preview showed (INV-11). A summary and a deterministic
+fingerprint over the records detect catalog drift between preview and confirm.
+
+Deliberately DB-free: the catalog snapshot dataclasses are defined here and the
+repo layer builds them. Only fields present in the file's canonical fields{}
+participate in a comparison — an absent column is untouched, never a change
+(§6.5.1); a present-but-empty cell resolves to the field's CLEAR_DEFAULTS entry
+— except a variant's position, whose default is the variant's 1-based file
+order within its product ("defaults to file order"), resolved here at diff time.
+Catalog variants/images absent from the file are likewise untouched (INV-10);
+file variants match catalog variants by their option-value combination (INV-13).
+"""
+from __future__ import annotations
+
+import hashlib
+import json
+from dataclasses import dataclass, field
+from decimal import Decimal
+
+from .models import CLEAR_DEFAULTS, CanonicalProduct, CanonicalVariant
+
+
+@dataclass
+class CatalogVariant:
+    id: int
+    options: tuple[str | None, str | None, str | None]
+    position: int
+    # sku, barcode, price (Decimal|None), cost, weight, weight_unit, volume,
+    # volume_unit, tax_id_1, tax_id_2, inventory_tracker, inventory_qty,
+    # variant_image (linked image source_url or None)
+    fields: dict[str, object]
+
+
+@dataclass
+class CatalogImage:
+    id: int
+    source_url: str
+    position: int
+    alt_text: str | None
+
+
+@dataclass
+class CatalogProduct:
+    id: int
+    handle: str
+    title: str
+    option_names: tuple[str | None, str | None, str | None]
+    # title, description_html, vendor, product_type, google_product_category,
+    # tags (list[str]), status, published (bool)
+    fields: dict[str, object]
+    variants: list[CatalogVariant]
+    images: list[CatalogImage]
+
+
+# ---------------------------------------------------------------------------
+# Apply plan — the typed twin of the preview records. confirm_draft executes
+# these; the values are resolved natives (Decimal, bool, list), never the
+# json-safe strings the records carry for display.
+# ---------------------------------------------------------------------------
+
+
+@dataclass
+class VariantPlan:
+    kind: str  # "add" | "update"
+    canonical: CanonicalVariant
+    catalog_id: int | None  # None for add
+    # 1-based index within the product's file variants — the position default.
+    file_order: int = 0
+    # field -> resolved after-value (update only); adds resolve from canonical.fields
+    changes: dict[str, object] = field(default_factory=dict)
+
+
+@dataclass
+class ImagePlan:
+    kind: str  # "add" | "update"
+    source_url: str
+    position: int
+    alt_text: str | None
+    image_id: int | None  # None for add
+    changes: dict[str, object] = field(default_factory=dict)  # subset of {"position","alt_text"}
+
+
+@dataclass
+class ProductPlan:
+    kind: str  # "add" | "update" | "unchanged" | "error"
+    canonical: CanonicalProduct
+    catalog: CatalogProduct | None
+    # field -> resolved after-value (update only; may include title/option*_name)
+    product_changes: dict[str, object] = field(default_factory=dict)
+    variant_plans: list[VariantPlan] = field(default_factory=list)
+    image_plans: list[ImagePlan] = field(default_factory=list)
+
+
+@dataclass(frozen=True)
+class DiffResult:
+    records: list[dict]
+    summary: dict
+    fingerprint: str
+    plan: list[ProductPlan]
+
+
+# Option-name presence markers in fields{} (see validate.py); the values are
+# compared via the option_names attribute, not through the generic field loop.
+_OPTION_NAME_FIELDS = ("option1_name", "option2_name", "option3_name")
+_SUMMARY_KEY = {"add": "adds", "update": "updates", "unchanged": "unchanged", "error": "errors"}
+
+
+def compute_diff(catalog: dict[str, CatalogProduct], products: list[CanonicalProduct]) -> DiffResult:
+    records: list[dict] = []
+    plan: list[ProductPlan] = []
+    summary = {"adds": 0, "updates": 0, "unchanged": 0, "errors": 0}
+    for product in products:
+        current = catalog.get(product.handle)
+        if product.errors:
+            product_plan = ProductPlan(kind="error", canonical=product, catalog=current)
+            detail: dict = {"errors": [e.as_json() for e in product.errors]}
+        elif current is None:
+            product_plan = _add_plan(product)
+            detail = _add_detail(product_plan)
+        else:
+            product_plan, detail = _update_plan(product, current)
+        kind = product_plan.kind
+        plan.append(product_plan)
+        records.append(
+            {
+                "handle": product.handle,
+                "title": product.title or (current.title if current else ""),
+                "kind": kind,
+                "variant_count": len(current.variants) if kind == "unchanged" else len(product.variants),
+                "detail": detail,
+            }
+        )
+        summary[_SUMMARY_KEY[kind]] += 1
+    fingerprint = hashlib.sha256(
+        json.dumps(records, sort_keys=True, separators=(",", ":")).encode()
+    ).hexdigest()
+    return DiffResult(records=records, summary=summary, fingerprint=fingerprint, plan=plan)
+
+
+def _add_plan(product: CanonicalProduct) -> ProductPlan:
+    return ProductPlan(
+        kind="add",
+        canonical=product,
+        catalog=None,
+        variant_plans=[
+            VariantPlan(kind="add", canonical=v, catalog_id=None, file_order=order)
+            for order, v in enumerate(product.variants, start=1)
+        ],
+        image_plans=[
+            ImagePlan(kind="add", source_url=i.source_url, position=i.position,
+                      alt_text=i.alt_text, image_id=None)
+            for i in product.images
+        ],
+    )
+
+
+def _add_detail(plan: ProductPlan) -> dict:
+    # On add, absent fields fall back to their defaults for display where one
+    # exists — the detail shows what will actually be set.
+    set_fields = resolved_product_fields(plan.canonical)
+    for field_name, default in CLEAR_DEFAULTS.items():
+        set_fields.setdefault(field_name, default)
+    return {
+        "set": {f: _json_safe(v) for f, v in set_fields.items()},
+        "option_names": list(plan.canonical.option_names),
+        "variants": [
+            {"options": list(vp.canonical.options),
+             "set": _resolved_variant_fields(vp.canonical, vp.file_order)}
+            for vp in plan.variant_plans
+        ],
+        "images": [
+            {"src": ip.source_url, "position": ip.position, "alt_text": ip.alt_text}
+            for ip in plan.image_plans
+        ],
+    }
+
+
+def _update_plan(product: CanonicalProduct, current: CatalogProduct) -> tuple[ProductPlan, dict]:
+    """One walk, two outputs: the resolved-value plan entries and the json-safe
+    record detail entries are appended side by side, so they can never diverge."""
+    product_changes: dict[str, object] = {}
+    changes: list[dict] = []
+    # Title is always file-present (required header column); "" means the block
+    # already carries an error and never reaches here.
+    if product.title and product.title != current.title:
+        product_changes["title"] = product.title
+        changes.append(_change("title", current.title, product.title))
+    for field_name, resolved in resolved_product_fields(product).items():
+        before = current.fields.get(field_name)
+        if resolved != before:
+            product_changes[field_name] = resolved
+            changes.append(_change(field_name, before, resolved))
+    for slot in (1, 2, 3):
+        if f"option{slot}_name" not in product.fields:
+            continue
+        before, after = current.option_names[slot - 1], product.option_names[slot - 1]
+        if after != before:
+            product_changes[f"option{slot}_name"] = after
+            changes.append(_change(f"option{slot}_name", before, after))
+
+    variant_plans: list[VariantPlan] = []
+    variant_entries: list[dict] = []
+    by_options = {v.options: v for v in current.variants}
+    for file_order, variant in enumerate(product.variants, start=1):
+        match = by_options.get(variant.options)
+        if match is None:
+            variant_plans.append(
+                VariantPlan(kind="add", canonical=variant, catalog_id=None, file_order=file_order)
+            )
+            variant_entries.append(
+                {"options": list(variant.options), "kind": "add",
+                 "set": _resolved_variant_fields(variant, file_order)}
+            )
+            continue
+        variant_changes: dict[str, object] = {}
+        variant_change_entries: list[dict] = []
+        for f, resolved in resolved_variant_fields(variant, file_order).items():
+            # position lives on the catalog variant as an attribute, not in
+            # fields{} — compare it explicitly (as images do for theirs).
+            before = match.position if f == "position" else match.fields.get(f)
+            if resolved != before:
+                variant_changes[f] = resolved
+                variant_change_entries.append(_change(f, before, resolved))
+        if variant_changes:
+            variant_plans.append(
+                VariantPlan(kind="update", canonical=variant, catalog_id=match.id,
+                            file_order=file_order, changes=variant_changes)
+            )
+            variant_entries.append(
+                {"options": list(variant.options), "kind": "update", "changes": variant_change_entries}
+            )
+
+    image_plans: list[ImagePlan] = []
+    image_entries: list[dict] = []
+    by_src = {i.source_url: i for i in current.images}
+    for image in product.images:
+        match = by_src.get(image.source_url)
+        if match is None:
+            image_plans.append(
+                ImagePlan(kind="add", source_url=image.source_url, position=image.position,
+                          alt_text=image.alt_text, image_id=None)
+            )
+            image_entries.append(
+                {"src": image.source_url, "kind": "add", "position": image.position, "alt_text": image.alt_text}
+            )
+            continue
+        image_changes: dict[str, object] = {}
+        image_change_entries: list[dict] = []
+        for f, before, after in (
+            ("position", match.position, image.position),
+            ("alt_text", match.alt_text, image.alt_text),
+        ):
+            if after != before:
+                image_changes[f] = after
+                image_change_entries.append(_change(f, before, after))
+        if image_changes:
+            image_plans.append(
+                ImagePlan(kind="update", source_url=image.source_url, position=image.position,
+                          alt_text=image.alt_text, image_id=match.id, changes=image_changes)
+            )
+            image_entries.append(
+                {"src": image.source_url, "kind": "update", "changes": image_change_entries}
+            )
+
+    detail: dict = {}
+    if changes:
+        detail["changes"] = changes
+    if variant_entries:
+        detail["variants"] = variant_entries
+    if image_entries:
+        detail["images"] = image_entries
+    kind = "update" if detail else "unchanged"
+    return (
+        ProductPlan(kind=kind, canonical=product, catalog=current, product_changes=product_changes,
+                    variant_plans=variant_plans, image_plans=image_plans),
+        detail,
+    )
+
+
+def resolved_fields(fields: dict[str, object]) -> dict[str, object]:
+    """File-present fields with None (an explicit clear) resolved to the default."""
+    return {f: (v if v is not None else CLEAR_DEFAULTS.get(f)) for f, v in fields.items()}
+
+
+def resolved_product_fields(product: CanonicalProduct) -> dict[str, object]:
+    """Resolved product-level fields, minus the option-name presence markers."""
+    return {
+        f: v for f, v in resolved_fields(product.fields).items() if f not in _OPTION_NAME_FIELDS
+    }
+
+
+def resolved_variant_fields(variant: CanonicalVariant, file_order: int) -> dict[str, object]:
+    """File-present variant fields with clears resolved. A cleared position has
+    no CLEAR_DEFAULTS entry — it resets to the variant's 1-based file order
+    within its product ("defaults to file order"), never to NULL."""
+    resolved = resolved_fields(variant.fields)
+    if "position" in resolved and resolved["position"] is None:
+        resolved["position"] = file_order
+    return resolved
+
+
+def _resolved_variant_fields(variant: CanonicalVariant, file_order: int) -> dict[str, object]:
+    return {f: _json_safe(v) for f, v in resolved_variant_fields(variant, file_order).items()}
+
+
+def _change(field_name: str, before: object, after: object) -> dict:
+    return {"field": field_name, "before": _json_safe(before), "after": _json_safe(after)}
+
+
+def _json_safe(value: object) -> object:
+    if isinstance(value, Decimal):
+        return str(value)
+    if isinstance(value, (tuple, list)):
+        return [_json_safe(v) for v in value]
+    return value

backend/app/domains/products/errors.py

@@ -0,0 +1,41 @@
+"""products domain errors (SD-0002 §6.4 error envelope codes)."""
+from __future__ import annotations
+
+
+class ProductsError(Exception):
+    """Base for products-domain errors."""
+
+
+class FileRejected(ProductsError):
+    """PUC-5a: the whole file is unusable; no draft is created. `code` is the §6.4
+    error code (not_csv | missing_required_column | unknown_dialect | too_many_rows |
+    file_too_large)."""
+
+    def __init__(self, code: str, message: str):
+        super().__init__(message)
+        self.code = code
+        self.message = message
+
+
+class DraftNotFound(ProductsError):
+    """No such draft for this storefront (or already discarded)."""
+
+
+class DraftExpired(ProductsError):
+    """The draft's validity window passed (§6.3 ~1 h)."""
+
+
+class PreviewStale(ProductsError):
+    """INV-11: the catalog changed since validation — the previewed diff no longer holds."""
+
+
+class NothingToApply(ProductsError):
+    """PUC-10: no adds and no updates — confirming would be a no-op."""
+
+
+class RunNotFound(ProductsError):
+    """No such import run for this storefront."""
+
+
+class EmptyCatalog(ProductsError):
+    """PUC-9: nothing to export (no products, or none matching the status filter)."""

backend/app/domains/products/models.py

@@ -0,0 +1,121 @@
+"""Canonical row model + column registry — the one model every dialect maps to (INV-17)."""
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+
+# §6.5.1 canonical columns, by level. Header detection, unknown-column warnings, and
+# validation all read from this registry.
+PRODUCT_COLUMNS: dict[str, str] = {
+    # column -> product field name
+    "Title": "title",
+    "Description": "description_html",
+    "Vendor": "vendor",
+    "Type": "product_type",
+    "Google Product Category": "google_product_category",
+    "Tags": "tags",
+    "Status": "status",
+    "Published": "published",
+    "Option1 Name": "option1_name",
+    "Option2 Name": "option2_name",
+    "Option3 Name": "option3_name",
+}
+VARIANT_COLUMNS: dict[str, str] = {
+    "Variant SKU": "sku",
+    "Variant Barcode": "barcode",
+    "Variant Price": "price",
+    "Variant Cost": "cost",
+    "Variant Weight": "weight",
+    "Variant Weight Unit": "weight_unit",
+    "Variant Volume": "volume",
+    "Variant Volume Unit": "volume_unit",
+    "Variant Tax ID 1": "tax_id_1",
+    "Variant Tax ID 2": "tax_id_2",
+    "Variant Inventory Tracker": "inventory_tracker",
+    "Variant Inventory Qty": "inventory_qty",
+    "Variant Position": "position",
+    "Variant Image": "variant_image",
+}
+OPTION_VALUE_COLUMNS = ("Option1 Value", "Option2 Value", "Option3 Value")
+IMAGE_COLUMNS = ("Image Src", "Image Position", "Image Alt Text")
+COMPONENT_COLUMNS = tuple(
+    f"Component {i} {kind}" for i in range(1, 11) for kind in ("SKU", "Quantity")
+)
+KNOWN_COLUMNS = (
+    {"Handle"}
+    | set(PRODUCT_COLUMNS)
+    | set(VARIANT_COLUMNS)
+    | set(OPTION_VALUE_COLUMNS)
+    | set(IMAGE_COLUMNS)
+    | set(COMPONENT_COLUMNS)
+)
+
+# Clearing a field (present-but-empty cell, §6.5.1) resets it to its default.
+CLEAR_DEFAULTS: dict[str, object] = {
+    "status": "active",
+    "published": True,
+    "product_type": "standalone",
+    "tags": [],
+}
+
+MAX_DATA_ROWS = 5_000  # INV-18
+MAX_FILE_BYTES = 10 * 1024 * 1024  # INV-18
+
+
+@dataclass(frozen=True)
+class Row:
+    """One CSV data row: 1-based file line number + the cells of known columns
+    present in the header (column name -> raw string, possibly empty)."""
+
+    line_number: int
+    cells: dict[str, str]
+
+
+@dataclass(frozen=True)
+class ParsedFile:
+    dialect: str
+    header: list[str]
+    unknown_columns: list[str]
+    rows: list[Row]
+
+
+@dataclass(frozen=True)
+class RowError:
+    line_number: int
+    column: str | None
+    message: str
+
+    def as_json(self) -> dict:
+        return {"line": self.line_number, "column": self.column, "message": self.message}
+
+
+@dataclass
+class CanonicalVariant:
+    line_number: int
+    options: tuple[str | None, str | None, str | None]
+    # field name -> normalized value; present only for columns in the file.
+    # value None == clear (reset to default/NULL).
+    fields: dict[str, object] = field(default_factory=dict)
+
+
+@dataclass
+class CanonicalImage:
+    line_number: int
+    source_url: str
+    position: int
+    alt_text: str | None
+
+
+@dataclass
+class CanonicalProduct:
+    first_line: int
+    handle: str
+    title: str  # "" when missing (the block then carries an error)
+    option_names: tuple[str | None, str | None, str | None] = (None, None, None)
+    fields: dict[str, object] = field(default_factory=dict)  # product-level, same semantics
+    variants: list[CanonicalVariant] = field(default_factory=list)
+    images: list[CanonicalImage] = field(default_factory=list)
+    errors: list[RowError] = field(default_factory=list)
+
+    @property
+    def valid(self) -> bool:
+        return not self.errors

backend/app/domains/products/repo.py

@@ -0,0 +1,496 @@
+"""products repo — the SQL layer for the import spine (SD-0002 §6.3 data model).
+
+Owns SQL only: the catalog snapshot the diff engine reads, import draft/run
+CRUD, and the apply primitives the confirm transaction calls. Business rules
+live in service.py and diff.py — nothing here validates, diffs, commits, or
+rolls back (the confirm flow runs the apply primitives inside its own
+transaction). Every catalog/draft/run query is storefront-scoped (INV-14).
+
+Dict payload conventions: functions feeding §6.4 API payloads (insert_draft,
+list_runs, get_run) return datetimes as `.isoformat()` strings; get_draft_row
+returns raw datetimes for the service's expiry check. TEXT[] columns bind/load
+as Python lists and NUMERIC loads as Decimal natively under psycopg 3.
+"""
+from __future__ import annotations
+
+import psycopg
+from psycopg import sql
+from psycopg.types.json import Jsonb
+
+from .diff import CatalogImage, CatalogProduct, CatalogVariant
+
+# ---------------------------------------------------------------------------
+# Catalog snapshot (diff input) + dashboard counts
+# ---------------------------------------------------------------------------
+
+
+def load_catalog(conn: psycopg.Connection, storefront_id: int) -> dict[str, CatalogProduct]:
+    """The storefront's full catalog, keyed by handle, in diff.py's snapshot shape."""
+    catalog: dict[str, CatalogProduct] = {}
+    by_id: dict[int, CatalogProduct] = {}
+    for row in conn.execute(
+        "SELECT id, handle, title, description_html, vendor, product_type,"
+        " google_product_category, tags, status, published,"
+        " option1_name, option2_name, option3_name"
+        " FROM product WHERE storefront_id = %s",
+        (storefront_id,),
+    ):
+        product = CatalogProduct(
+            id=row[0],
+            handle=row[1],
+            title=row[2],
+            option_names=(row[10], row[11], row[12]),
+            fields={
+                "title": row[2],
+                "description_html": row[3],
+                "vendor": row[4],
+                "product_type": row[5],
+                "google_product_category": row[6],
+                "tags": row[7],
+                "status": row[8],
+                "published": row[9],
+            },
+            variants=[],
+            images=[],
+        )
+        catalog[product.handle] = product
+        by_id[product.id] = product
+    for row in conn.execute(
+        "SELECT v.product_id, v.id, v.position,"
+        " v.option1_value, v.option2_value, v.option3_value,"
+        " v.sku, v.barcode, v.price, v.cost, v.weight, v.weight_unit,"
+        " v.volume, v.volume_unit, v.tax_id_1, v.tax_id_2,"
+        " v.inventory_tracker, v.inventory_qty, i.source_url"
+        " FROM variant v"
+        " JOIN product p ON p.id = v.product_id"
+        " LEFT JOIN product_image i ON i.id = v.image_id"
+        " WHERE p.storefront_id = %s"
+        " ORDER BY v.product_id, v.position, v.id",
+        (storefront_id,),
+    ):
+        by_id[row[0]].variants.append(
+            CatalogVariant(
+                id=row[1],
+                options=(row[3], row[4], row[5]),
+                position=row[2],
+                fields={
+                    "sku": row[6],
+                    "barcode": row[7],
+                    "price": row[8],
+                    "cost": row[9],
+                    "weight": row[10],
+                    "weight_unit": row[11],
+                    "volume": row[12],
+                    "volume_unit": row[13],
+                    "tax_id_1": row[14],
+                    "tax_id_2": row[15],
+                    "inventory_tracker": row[16],
+                    "inventory_qty": row[17],
+                    "variant_image": row[18],
+                },
+            )
+        )
+    for row in conn.execute(
+        "SELECT i.product_id, i.id, i.source_url, i.position, i.alt_text"
+        " FROM product_image i"
+        " JOIN product p ON p.id = i.product_id"
+        " WHERE p.storefront_id = %s"
+        " ORDER BY i.product_id, i.position, i.id",
+        (storefront_id,),
+    ):
+        by_id[row[0]].images.append(
+            CatalogImage(id=row[1], source_url=row[2], position=row[3], alt_text=row[4])
+        )
+    return catalog
+
+
+_EXPORT_STATUSES = ("all", "active", "draft", "archived")
+
+
+def export_catalog(
+    conn: psycopg.Connection, storefront_id: int, status_filter: str
+) -> list[CatalogProduct]:
+    """The storefront's catalog as an ordered snapshot list, optionally filtered
+    by product status (PUC-9). Reuses load_catalog's snapshot builder; the
+    catalog fits in memory (≤5k rows, INV-18). Ordered by handle for a stable,
+    deterministic export."""
+    catalog = load_catalog(conn, storefront_id)
+    products = sorted(catalog.values(), key=lambda p: p.handle)
+    if status_filter and status_filter != "all":
+        products = [p for p in products if p.fields.get("status") == status_filter]
+    return products
+
+
+def product_count(conn: psycopg.Connection, storefront_id: int) -> int:
+    return conn.execute(
+        "SELECT count(*) FROM product WHERE storefront_id = %s", (storefront_id,)
+    ).fetchone()[0]
+
+
+def image_problem_count(conn: psycopg.Connection, storefront_id: int) -> int:
+    return conn.execute(
+        "SELECT count(*) FROM product_image i"
+        " JOIN product p ON p.id = i.product_id"
+        " WHERE p.storefront_id = %s"
+        " AND i.status IN ('rejected_low_res', 'rejected_not_image', 'failed')",
+        (storefront_id,),
+    ).fetchone()[0]
+
+
+def latest_run_id(conn: psycopg.Connection, storefront_id: int) -> int | None:
+    row = conn.execute(
+        "SELECT id FROM import_run WHERE storefront_id = %s"
+        " ORDER BY created_at DESC, id DESC LIMIT 1",
+        (storefront_id,),
+    ).fetchone()
+    return row[0] if row else None
+
+
+# ---------------------------------------------------------------------------
+# Import drafts (preview server side, INV-11)
+# ---------------------------------------------------------------------------
+
+
+def insert_draft(
+    conn: psycopg.Connection,
+    storefront_id: int,
+    account_id: int,
+    file_name: str,
+    dialect: str,
+    file_bytes: bytes,
+    summary: dict,
+    records: list,
+    fingerprint: str,
+    unknown_columns: list[str],
+) -> dict:
+    """Create a draft (expires in 1 hour); returns the §6.4 draft payload."""
+    row = conn.execute(
+        "INSERT INTO import_draft"
+        " (storefront_id, account_id, file_name, dialect, file_bytes,"
+        "  summary, records, fingerprint, unknown_columns, expires_at)"
+        " VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, now() + interval '1 hour')"
+        " RETURNING id, expires_at",
+        (
+            storefront_id,
+            account_id,
+            file_name,
+            dialect,
+            file_bytes,
+            Jsonb(summary),
+            Jsonb(records),
+            fingerprint,
+            unknown_columns,
+        ),
+    ).fetchone()
+    return {
+        "id": row[0],
+        "file_name": file_name,
+        "dialect": dialect,
+        "summary": summary,
+        "unknown_columns": unknown_columns,
+        "expires_at": row[1].isoformat(),
+    }
+
+
+def get_draft_row(conn: psycopg.Connection, storefront_id: int, draft_id: int) -> dict | None:
+    row = conn.execute(
+        "SELECT id, storefront_id, account_id, file_name, dialect, file_bytes,"
+        " summary, records, fingerprint, unknown_columns, expires_at, created_at"
+        " FROM import_draft WHERE id = %s AND storefront_id = %s",
+        (draft_id, storefront_id),
+    ).fetchone()
+    if row is None:
+        return None
+    columns = (
+        "id",
+        "storefront_id",
+        "account_id",
+        "file_name",
+        "dialect",
+        "file_bytes",
+        "summary",
+        "records",
+        "fingerprint",
+        "unknown_columns",
+        "expires_at",
+        "created_at",
+    )
+    record = dict(zip(columns, row))
+    # BYTEA loads as memoryview; the service expects bytes.
+    record["file_bytes"] = bytes(record["file_bytes"])
+    return record
+
+
+def draft_records(
+    conn: psycopg.Connection,
+    storefront_id: int,
+    draft_id: int,
+    kind: str | None,
+    limit: int,
+    offset: int,
+) -> list[dict]:
+    """The draft's preview records, order-preserving, optionally filtered by kind."""
+    rows = conn.execute(
+        "SELECT rec FROM import_draft d,"
+        " jsonb_array_elements(d.records) WITH ORDINALITY AS r(rec, ord)"
+        " WHERE d.id = %(draft_id)s AND d.storefront_id = %(storefront_id)s"
+        " AND (%(kind)s::text IS NULL OR rec->>'kind' = %(kind)s)"
+        " ORDER BY ord LIMIT %(limit)s OFFSET %(offset)s",
+        {
+            "draft_id": draft_id,
+            "storefront_id": storefront_id,
+            "kind": kind,
+            "limit": limit,
+            "offset": offset,
+        },
+    ).fetchall()
+    return [row[0] for row in rows]
+
+
+def delete_draft(conn: psycopg.Connection, storefront_id: int, draft_id: int) -> None:
+    conn.execute(
+        "DELETE FROM import_draft WHERE id = %s AND storefront_id = %s",
+        (draft_id, storefront_id),
+    )
+
+
+def sweep_expired_drafts(conn: psycopg.Connection) -> None:
+    conn.execute("DELETE FROM import_draft WHERE expires_at < now()")
+
+
+# ---------------------------------------------------------------------------
+# Import runs (history, PUC-8)
+# ---------------------------------------------------------------------------
+
+_TERMINAL_RUN_STATUSES = ("complete", "complete_with_problems")
+
+
+def insert_run(
+    conn: psycopg.Connection,
+    storefront_id: int,
+    account_id: int,
+    file_name: str,
+    dialect: str,
+    added: int,
+    updated: int,
+    errored: int,
+    status: str,
+) -> int:
+    return conn.execute(
+        "INSERT INTO import_run"
+        " (storefront_id, account_id, file_name, dialect,"
+        "  products_added, products_updated, rows_errored, status, completed_at)"
+        " VALUES (%s, %s, %s, %s, %s, %s, %s, %s, CASE WHEN %s THEN now() END)"
+        " RETURNING id",
+        (
+            storefront_id,
+            account_id,
+            file_name,
+            dialect,
+            added,
+            updated,
+            errored,
+            status,
+            status in _TERMINAL_RUN_STATUSES,
+        ),
+    ).fetchone()[0]
+
+
+def insert_run_errors(conn: psycopg.Connection, run_id: int, errors: list[dict]) -> None:
+    """Record per-row errors (RowError.as_json shape: line/column/message)."""
+    if not errors:
+        return
+    with conn.cursor() as cur:
+        cur.executemany(
+            "INSERT INTO import_run_error (run_id, line_number, column_name, message)"
+            " VALUES (%s, %s, %s, %s)",
+            [(run_id, e["line"], e["column"], e["message"]) for e in errors],
+        )
+
+
+_RUN_SELECT = (
+    "SELECT r.id, r.file_name, r.dialect, r.created_at, r.completed_at, r.status,"
+    " a.email, r.products_added, r.products_updated, r.rows_errored"
+    " FROM import_run r JOIN account a ON a.id = r.account_id"
+)
+
+
+def _run_dict(row: tuple) -> dict:
+    return {
+        "id": row[0],
+        "file_name": row[1],
+        "dialect": row[2],
+        "created_at": row[3].isoformat(),
+        "completed_at": row[4].isoformat() if row[4] is not None else None,
+        "status": row[5],
+        "by": row[6],
+        "products_added": row[7],
+        "products_updated": row[8],
+        "rows_errored": row[9],
+    }
+
+
+def list_runs(
+    conn: psycopg.Connection, storefront_id: int, limit: int, offset: int
+) -> list[dict]:
+    rows = conn.execute(
+        _RUN_SELECT
+        + " WHERE r.storefront_id = %s ORDER BY r.created_at DESC, r.id DESC"
+        " LIMIT %s OFFSET %s",
+        (storefront_id, limit, offset),
+    ).fetchall()
+    return [_run_dict(row) for row in rows]
+
+
+def get_run(conn: psycopg.Connection, storefront_id: int, run_id: int) -> dict | None:
+    row = conn.execute(
+        _RUN_SELECT + " WHERE r.storefront_id = %s AND r.id = %s",
+        (storefront_id, run_id),
+    ).fetchone()
+    if row is None:
+        return None
+    run = _run_dict(row)
+    run["errors"] = [
+        {"line": line, "column": column, "message": message}
+        for line, column, message in conn.execute(
+            "SELECT line_number, column_name, message FROM import_run_error"
+            " WHERE run_id = %s ORDER BY line_number, id",
+            (run_id,),
+        )
+    ]
+    # SLICE-7 fills these; the §6.4 payload shape is stable from SLICE-5 on.
+    run["image_progress"] = {"done": 0, "total": 0}
+    run["image_outcomes"] = []
+    return run
+
+
+# ---------------------------------------------------------------------------
+# Apply primitives — called inside the confirm transaction (Task 8); no commits.
+# ---------------------------------------------------------------------------
+
+
+def insert_product(
+    conn: psycopg.Connection,
+    storefront_id: int,
+    handle: str,
+    resolved_fields: dict,
+    option_names: tuple[str | None, str | None, str | None],
+) -> int:
+    """INSERT with only the file-present fields; absent ones take column defaults."""
+    columns = ["storefront_id", "handle", "option1_name", "option2_name", "option3_name"]
+    values: list[object] = [storefront_id, handle, *option_names]
+    for field_name, value in resolved_fields.items():
+        columns.append(field_name)
+        values.append(value)
+    query = sql.SQL("INSERT INTO product ({}) VALUES ({}) RETURNING id").format(
+        sql.SQL(", ").join(sql.Identifier(c) for c in columns),
+        sql.SQL(", ").join(sql.Placeholder() for _ in columns),
+    )
+    return conn.execute(query, values).fetchone()[0]
+
+
+def update_product(conn: psycopg.Connection, product_id: int, changed_fields: dict) -> None:
+    if not changed_fields:
+        return
+    assignments = [
+        sql.SQL("{} = {}").format(sql.Identifier(f), sql.Placeholder())
+        for f in changed_fields
+    ]
+    query = sql.SQL("UPDATE product SET {}, updated_at = now() WHERE id = {}").format(
+        sql.SQL(", ").join(assignments), sql.Placeholder()
+    )
+    conn.execute(query, [*changed_fields.values(), product_id])
+
+
+def insert_variant(
+    conn: psycopg.Connection,
+    product_id: int,
+    position: int,
+    options: tuple[str | None, str | None, str | None],
+    resolved_fields: dict,
+    image_id: int | None,
+) -> int:
+    # variant_image is not a column — the caller translates it to image_id; position
+    # is the explicit param. Filter both defensively.
+    fields = {
+        k: v for k, v in resolved_fields.items() if k != "variant_image" and k != "position"
+    }
+    columns = [
+        "product_id",
+        "position",
+        "option1_value",
+        "option2_value",
+        "option3_value",
+        "image_id",
+    ]
+    values: list[object] = [product_id, position, *options, image_id]
+    for field_name, value in fields.items():
+        columns.append(field_name)
+        values.append(value)
+    query = sql.SQL("INSERT INTO variant ({}) VALUES ({}) RETURNING id").format(
+        sql.SQL(", ").join(sql.Identifier(c) for c in columns),
+        sql.SQL(", ").join(sql.Placeholder() for _ in columns),
+    )
+    return conn.execute(query, values).fetchone()[0]
+
+
+def update_variant(
+    conn: psycopg.Connection,
+    variant_id: int,
+    changed_fields: dict,
+    image_id: int | None | type(...) = ...,
+) -> None:
+    """Dynamic UPDATE; image_id's Ellipsis default means "don't touch image_id"."""
+    fields = {
+        k: v for k, v in changed_fields.items() if k != "variant_image"
+    }
+    assignments = [
+        sql.SQL("{} = {}").format(sql.Identifier(f), sql.Placeholder()) for f in fields
+    ]
+    values: list[object] = list(fields.values())
+    if image_id is not ...:
+        assignments.append(sql.SQL("image_id = {}").format(sql.Placeholder()))
+        values.append(image_id)
+    if not assignments:
+        return
+    query = sql.SQL("UPDATE variant SET {}, updated_at = now() WHERE id = {}").format(
+        sql.SQL(", ").join(assignments), sql.Placeholder()
+    )
+    conn.execute(query, [*values, variant_id])
+
+
+def get_or_create_image(
+    conn: psycopg.Connection,
+    product_id: int,
+    source_url: str,
+    position: int,
+    alt_text: str | None,
+    run_id: int,
+) -> int:
+    """Image identity within a product is source_url (§6.3); existing rows are
+    returned untouched — diff emits explicit image update entries for position/alt."""
+    row = conn.execute(
+        "SELECT id FROM product_image WHERE product_id = %s AND source_url = %s",
+        (product_id, source_url),
+    ).fetchone()
+    if row is not None:
+        return row[0]
+    return conn.execute(
+        "INSERT INTO product_image (product_id, source_url, position, alt_text, import_run_id)"
+        " VALUES (%s, %s, %s, %s, %s) RETURNING id",
+        (product_id, source_url, position, alt_text, run_id),
+    ).fetchone()[0]
+
+
+def update_image(conn: psycopg.Connection, image_id: int, changed_fields: dict) -> None:
+    """Subset of {position, alt_text}."""
+    if not changed_fields:
+        return
+    assignments = [
+        sql.SQL("{} = {}").format(sql.Identifier(f), sql.Placeholder())
+        for f in changed_fields
+    ]
+    query = sql.SQL("UPDATE product_image SET {} WHERE id = {}").format(
+        sql.SQL(", ").join(assignments), sql.Placeholder()
+    )
+    conn.execute(query, [*changed_fields.values(), image_id])

backend/app/domains/products/sample.csv

@@ -0,0 +1,6 @@
+Handle,Title,Description,Vendor,Type,Google Product Category,Tags,Status,Published,Option1 Name,Option1 Value,Option2 Name,Option2 Value,Variant SKU,Variant Price,Variant Inventory Qty,Image Src,Image Position,Image Alt Text
+moon-mug,Moon Mug,"<p>A ceramic mug glazed in moonlight grey.</p>",Wiggle Goods,standalone,Home & Garden > Kitchen & Dining,"kitchen, mugs",active,TRUE,,,,,WG-MUG-001,18.00,40,https://images.example.com/moon-mug.jpg,1,Moon Mug on a desk
+star-tee,Star Tee,"<p>Soft cotton tee with a hand-printed star.</p>",Wiggle Goods,standalone,Apparel & Accessories > Clothing,"apparel, tees",active,TRUE,Size,S,Color,Indigo,WG-TEE-S,24.00,12,https://images.example.com/star-tee.jpg,1,Star Tee flat lay
+star-tee,,,,,,,,,,M,,Indigo,WG-TEE-M,24.00,18,,,
+star-tee,,,,,,,,,,L,,Indigo,WG-TEE-L,26.00,9,,,
+star-tee,,,,,,,,,,,,,,,,https://images.example.com/star-tee-back.jpg,2,Star Tee back print

backend/app/domains/products/serialize.py

@@ -0,0 +1,119 @@
+"""Canonical serializer — CatalogProduct snapshot → canonical CSV (SD-0002 §6.5.5).
+
+The export half of "one codec, two directions": this writes exactly the columns
+codec.py/validate.py parse, in a row grammar (§6.5.1) the validator regroups
+identically — so re-importing an unmodified export diffs to nothing (INV-12).
+DB-free, like diff.py: it consumes the same CatalogProduct snapshot the diff
+engine reads (repo.load_catalog), and the service streams the result.
+"""
+from __future__ import annotations
+
+import csv
+import io
+from collections.abc import Iterable, Iterator
+from decimal import Decimal
+
+from .diff import CatalogProduct
+from .models import (
+    IMAGE_COLUMNS,
+    OPTION_VALUE_COLUMNS,
+    PRODUCT_COLUMNS,
+    VARIANT_COLUMNS,
+)
+
+# Canonical column order: Handle, then product, option-value, variant, image
+# columns. A superset of everything the parser knows (models.KNOWN_COLUMNS minus
+# the #15-reserved Component columns, which export never emits).
+HEADER: list[str] = [
+    "Handle",
+    *PRODUCT_COLUMNS,
+    *OPTION_VALUE_COLUMNS,
+    *VARIANT_COLUMNS,
+    *IMAGE_COLUMNS,
+]
+
+# field name -> column name, inverting the model registry (the parser reads
+# column->field; the serializer writes field->column).
+_PRODUCT_FIELD_TO_COL = {field: col for col, field in PRODUCT_COLUMNS.items()}
+_VARIANT_FIELD_TO_COL = {field: col for col, field in VARIANT_COLUMNS.items()}
+
+
+def _cell(value: object) -> str:
+    """Serialize one value to its canonical cell text (the parse inverse)."""
+    if value is None:
+        return ""
+    if isinstance(value, bool):
+        return "TRUE" if value else "FALSE"
+    if isinstance(value, Decimal):
+        return str(value)
+    if isinstance(value, (list, tuple)):
+        return ", ".join(str(v) for v in value)
+    return str(value)
+
+
+def catalog_to_csv(products: Iterable[CatalogProduct]) -> Iterator[str]:
+    """Stream canonical CSV text, header first, one product block at a time."""
+    buf = io.StringIO()
+    writer = csv.writer(buf)
+    writer.writerow(HEADER)
+    yield _drain(buf)
+    for product in products:
+        for row in _product_rows(product):
+            writer.writerow([row.get(col, "") for col in HEADER])
+        yield _drain(buf)
+
+
+def _drain(buf: io.StringIO) -> str:
+    text = buf.getvalue()
+    buf.seek(0)
+    buf.truncate(0)
+    return text
+
+
+def _product_rows(product: CatalogProduct) -> list[dict[str, str]]:
+    """The product's CSV rows (§6.5.1 grammar): product fields + option names on
+    the first row; one variant per row; images interleaved; image-only rows when
+    a product has more images than variants."""
+    base = {"Handle": product.handle, "Title": product.title}
+    for field, col in _PRODUCT_FIELD_TO_COL.items():
+        if field in product.fields:
+            base[col] = _cell(product.fields[field])
+    for slot, name in enumerate(product.option_names, start=1):
+        if name:
+            base[f"Option{slot} Name"] = name
+
+    count = max(len(product.variants), len(product.images))
+    rows: list[dict[str, str]] = []
+    for i in range(count):
+        # Row 0 carries the product-level fields; later rows carry only Handle.
+        row = dict(base) if i == 0 else {"Handle": product.handle}
+        if i < len(product.variants):
+            _write_variant(row, product, product.variants[i])
+        if i < len(product.images):
+            _write_image(row, product.images[i])
+        rows.append(row)
+    return rows
+
+
+def _write_image(row: dict[str, str], image) -> None:
+    row["Image Src"] = image.source_url
+    row["Image Position"] = str(image.position)
+    if image.alt_text is not None:
+        row["Image Alt Text"] = image.alt_text
+
+
+def _write_variant(row: dict[str, str], product: CatalogProduct, variant) -> None:
+    """Fill a row's option-value + variant columns for one variant."""
+    for slot, value in enumerate(variant.options, start=1):
+        # Only emit an option value when the product actually has that option
+        # (a no-option product's single variant carries all-NULL options).
+        if product.option_names[slot - 1] and value is not None:
+            row[f"Option{slot} Value"] = value
+    # position is a CatalogVariant attribute, not a fields{} entry — emit it
+    # explicitly. An empty Variant Position cell re-imports as "reset to file
+    # order", so a non-sequential stored position would round-trip to an update
+    # (INV-12). (Like _write_image, which emits its position attribute.)
+    row["Variant Position"] = str(variant.position)
+    for field, col in _VARIANT_FIELD_TO_COL.items():
+        if field in variant.fields:
+            row[col] = _cell(variant.fields[field])

backend/app/domains/products/service.py

@@ -0,0 +1,263 @@
+"""products service — the import/export use-case orchestration (SD-0002 §6.5).
+
+Coordinates codec → validate → diff → repo; owns transaction boundaries (repo
+never commits). Preview is read-only against catalog tables (INV-11): validation
+writes exactly one row — the import_draft. TEL events per §9.1.
+"""
+from __future__ import annotations
+
+import time
+from collections.abc import Iterator
+from datetime import datetime, timezone
+
+import psycopg
+
+from app.platform import telemetry
+
+from . import codec, diff, repo, serialize, validate
+from .errors import (
+    DraftExpired,
+    DraftNotFound,
+    EmptyCatalog,
+    NothingToApply,
+    PreviewStale,
+    RunNotFound,
+)
+
+
+def import_validate(conn: psycopg.Connection, storefront_id: int, account_id: int,
+                    file_name: str, data: bytes) -> dict:
+    """Upload → validate → diff → persist draft (PUC-2/3; INV-11). Raises FileRejected."""
+    started = time.monotonic()
+    # Commit the sweep before parsing: a FileRejected mid-parse must not roll
+    # back expired-draft cleanup along with it.
+    repo.sweep_expired_drafts(conn)
+    conn.commit()
+    parsed = codec.parse_csv(data)
+    products = validate.build_products(parsed)
+    catalog = repo.load_catalog(conn, storefront_id)
+    diff_result = diff.compute_diff(catalog, products)
+    draft = repo.insert_draft(
+        conn, storefront_id, account_id, file_name, parsed.dialect, data,
+        diff_result.summary, diff_result.records, diff_result.fingerprint,
+        parsed.unknown_columns,
+    )
+    conn.commit()
+    telemetry.emit(
+        "import_draft_created",
+        storefront_id=storefront_id,
+        dialect=parsed.dialect,
+        row_count=len(parsed.rows),
+        adds=diff_result.summary["adds"],
+        updates=diff_result.summary["updates"],
+        unchanged=diff_result.summary["unchanged"],
+        errors=diff_result.summary["errors"],
+        unknown_columns_count=len(parsed.unknown_columns),
+        duration_ms=int((time.monotonic() - started) * 1000),
+    )
+    return draft
+
+
+def _live_draft_row(conn: psycopg.Connection, storefront_id: int, draft_id: int) -> dict:
+    """The draft row if it exists and hasn't expired; expiry deletes lazily (§6.3)."""
+    row = repo.get_draft_row(conn, storefront_id, draft_id)
+    if row is None:
+        raise DraftNotFound()
+    if row["expires_at"] < datetime.now(timezone.utc):
+        repo.delete_draft(conn, storefront_id, draft_id)
+        conn.commit()
+        raise DraftExpired()
+    return row
+
+
+def get_draft(conn: psycopg.Connection, storefront_id: int, draft_id: int) -> dict:
+    """The §6.4 draft payload — never file_bytes or the full records list."""
+    row = _live_draft_row(conn, storefront_id, draft_id)
+    return {
+        "id": row["id"],
+        "file_name": row["file_name"],
+        "dialect": row["dialect"],
+        "summary": row["summary"],
+        "unknown_columns": row["unknown_columns"],
+        "expires_at": row["expires_at"].isoformat(),
+    }
+
+
+def get_draft_records(conn: psycopg.Connection, storefront_id: int, draft_id: int,
+                      kind: str | None = None, limit: int = 100, offset: int = 0) -> list[dict]:
+    """The draft's preview records, paged, optionally filtered by kind (PUC-3)."""
+    _live_draft_row(conn, storefront_id, draft_id)
+    return repo.draft_records(conn, storefront_id, draft_id, kind, limit, offset)
+
+
+def discard_draft(conn: psycopg.Connection, storefront_id: int, draft_id: int) -> None:
+    """Delete the draft, no trace kept; idempotent — an absent draft is fine (PUC-3a)."""
+    repo.delete_draft(conn, storefront_id, draft_id)
+    conn.commit()
+
+
+def confirm_draft(conn: psycopg.Connection, storefront_id: int, account_id: int,
+                  draft_id: int) -> int:
+    """Apply the previewed diff in one transaction (PUC-4; INV-10/11).
+
+    Everything is re-derived from the draft's stored file bytes against the live
+    catalog; a fingerprint mismatch means the catalog drifted since preview
+    (PreviewStale — the draft is kept so the merchant can re-validate). The apply
+    executes the typed plan compute_diff built alongside the preview records, so
+    what lands is exactly what the preview showed. rows_errored counts the
+    import_run_error rows recorded (one per RowError), which is what the run
+    detail's error table shows; the preview's errors tile counts error *products*.
+    """
+    started = time.monotonic()
+    row = _live_draft_row(conn, storefront_id, draft_id)
+    parsed = codec.parse_csv(row["file_bytes"])
+    products = validate.build_products(parsed)
+    catalog = repo.load_catalog(conn, storefront_id)
+    diff_result = diff.compute_diff(catalog, products)
+    if diff_result.fingerprint != row["fingerprint"]:
+        # Release the read snapshot; nothing written.
+        conn.rollback()
+        raise PreviewStale()
+    summary_counts = diff_result.summary
+    if summary_counts["adds"] + summary_counts["updates"] == 0:
+        # Release the read snapshot; nothing written.
+        conn.rollback()
+        raise NothingToApply()
+    error_rows = [
+        error.as_json()
+        for plan in diff_result.plan if plan.kind == "error"
+        for error in plan.canonical.errors
+    ]
+    try:
+        run_id = repo.insert_run(
+            conn, storefront_id, account_id, row["file_name"], row["dialect"],
+            added=summary_counts["adds"], updated=summary_counts["updates"],
+            errored=len(error_rows), status="complete",
+        )
+        for plan in diff_result.plan:
+            _apply_product_plan(conn, storefront_id, plan, run_id)
+        repo.insert_run_errors(conn, run_id, error_rows)
+        repo.delete_draft(conn, storefront_id, draft_id)
+        conn.commit()
+    except Exception as exc:
+        conn.rollback()
+        telemetry.emit(
+            "import_apply_failed",
+            draft_id=draft_id,
+            storefront_id=storefront_id,
+            error_class=type(exc).__name__,
+        )
+        raise
+    telemetry.emit(
+        "import_run_completed",
+        run_id=run_id,
+        storefront_id=storefront_id,
+        added=summary_counts["adds"],
+        updated=summary_counts["updates"],
+        errored=len(error_rows),
+        duration_ms=int((time.monotonic() - started) * 1000),
+    )
+    return run_id
+
+
+def _apply_product_plan(conn: psycopg.Connection, storefront_id: int,
+                        plan: diff.ProductPlan, run_id: int) -> None:
+    """Execute one product's plan inside the confirm transaction (no commits here)."""
+    if plan.kind == "add":
+        # Title is a canonical attribute, not a fields{} entry — non-error
+        # products always carry one (validate guarantees it).
+        product_fields = {"title": plan.canonical.title}
+        product_fields.update(diff.resolved_product_fields(plan.canonical))
+        product_id = repo.insert_product(
+            conn, storefront_id, plan.canonical.handle, product_fields, plan.canonical.option_names
+        )
+        image_ids: dict[str, int] = {}
+    elif plan.kind == "update":
+        product_id = plan.catalog.id
+        repo.update_product(conn, product_id, plan.product_changes)
+        image_ids = {image.source_url: image.id for image in plan.catalog.images}
+    else:
+        return
+
+    # Images first, so variants' variant_image URLs resolve to ids: validate puts
+    # every variant_image URL into canonical.images, so each URL is in either the
+    # catalog map (existing image) or the adds below.
+    for image_plan in plan.image_plans:
+        if image_plan.kind == "add":
+            image_ids[image_plan.source_url] = repo.get_or_create_image(
+                conn, product_id, image_plan.source_url, image_plan.position,
+                image_plan.alt_text, run_id,
+            )
+        else:
+            repo.update_image(conn, image_plan.image_id, image_plan.changes)
+
+    for variant_plan in plan.variant_plans:
+        if variant_plan.kind == "add":
+            fields = diff.resolved_variant_fields(variant_plan.canonical, variant_plan.file_order)
+            # diff time resolved any cleared position to file order; the
+            # file_order fallback covers an absent position column.
+            position = fields.get("position") or variant_plan.file_order
+            url = fields.get("variant_image")
+            image_id = image_ids[url] if url else None
+            repo.insert_variant(
+                conn, product_id, position, variant_plan.canonical.options, fields, image_id
+            )
+        elif "variant_image" in variant_plan.changes:
+            url = variant_plan.changes["variant_image"]
+            repo.update_variant(
+                conn, variant_plan.catalog_id, variant_plan.changes,
+                image_id=image_ids[url] if url else None,
+            )
+        else:
+            repo.update_variant(conn, variant_plan.catalog_id, variant_plan.changes)
+
+
+def list_runs(conn: psycopg.Connection, storefront_id: int,
+              limit: int = 50, offset: int = 0) -> list[dict]:
+    """The storefront's import history, newest first (PUC-8)."""
+    return repo.list_runs(conn, storefront_id, limit, offset)
+
+
+def get_run(conn: psycopg.Connection, storefront_id: int, run_id: int) -> dict:
+    """One run's §6.4 detail payload, errors included."""
+    run = repo.get_run(conn, storefront_id, run_id)
+    if run is None:
+        raise RunNotFound()
+    return run
+
+
+def export_catalog(
+    conn: psycopg.Connection, storefront_id: int, status_filter: str
+) -> Iterator[str]:
+    """Stream the storefront's catalog as canonical CSV (PUC-9; INV-12 codec).
+
+    Read-only: builds the snapshot, then streams the serializer over it. TEL-3
+    is emitted once the stream is exhausted, with the product count and elapsed
+    time. Raises EmptyCatalog before yielding anything if the (filtered) catalog
+    is empty, so the BFF can answer 409 cleanly with no partial body.
+    """
+    started = time.monotonic()
+    snapshot = repo.export_catalog(conn, storefront_id, status_filter)
+    if not snapshot:
+        raise EmptyCatalog()
+
+    def _stream() -> Iterator[str]:
+        yield from serialize.catalog_to_csv(snapshot)
+        telemetry.emit(
+            "catalog_exported",
+            storefront_id=storefront_id,
+            status_filter=status_filter,
+            product_count=len(snapshot),
+            duration_ms=int((time.monotonic() - started) * 1000),
+        )
+
+    return _stream()
+
+
+def summary(conn: psycopg.Connection, storefront_id: int) -> dict:
+    """The products dashboard counts (§6.4)."""
+    return {
+        "product_count": repo.product_count(conn, storefront_id),
+        "image_problem_count": repo.image_problem_count(conn, storefront_id),
+        "latest_run_id": repo.latest_run_id(conn, storefront_id),
+    }

backend/app/domains/products/validate.py

@@ -0,0 +1,299 @@
+"""Row validation — ParsedFile rows → canonical products + row errors (SD-0002 §6.5.1).
+
+The codec (codec.py) handles file-level gates; this module is the row-semantics
+half of the PUC-5 import spine. It groups consecutive rows sharing a Handle into
+product blocks (Shopify's grammar), normalizes product/variant/image fields, and
+records every rule violation as a merchant-language RowError. Errors never raise:
+an error poisons its whole product block (the product previews as kind="error"
+and is excluded from apply) while parsing continues so the merchant gets a
+complete accounting in one pass (BUC-1a). Description HTML is sanitized with nh3
+on the way in (INV-15).
+"""
+from __future__ import annotations
+
+import re
+from decimal import Decimal, InvalidOperation
+
+import nh3
+
+from .models import (
+    COMPONENT_COLUMNS,
+    OPTION_VALUE_COLUMNS,
+    PRODUCT_COLUMNS,
+    VARIANT_COLUMNS,
+    CanonicalImage,
+    CanonicalProduct,
+    CanonicalVariant,
+    ParsedFile,
+    Row,
+    RowError,
+)
+
+_HANDLE_RE = re.compile(r"^[a-z0-9-]+$")
+_STATUSES = {"draft", "active", "archived"}
+# Title is handled as an attribute, not via fields{}. Option names live in BOTH
+# .option_names (the values) and fields{} (the file-presence signal the diff
+# needs: absent column == untouched, never a clear).
+_ATTRIBUTE_COLUMNS = {"Title"}
+# Sentinel: the cell failed normalization (the error is already recorded).
+_INVALID = object()
+
+
+def build_products(parsed: ParsedFile) -> list[CanonicalProduct]:
+    """Group rows into product blocks and validate every §6.5.1 rule."""
+    products: list[CanonicalProduct] = []
+    closed_handles: set[str] = set()
+    block: list[Row] = []
+
+    def flush() -> None:
+        nonlocal block
+        if block:
+            closed_handles.add(block[0].cells["Handle"])
+            products.append(_build_block(block))
+            block = []
+
+    for row in parsed.rows:
+        handle = row.cells.get("Handle", "")
+        if block and handle == block[0].cells["Handle"]:
+            block.append(row)
+            continue
+        flush()
+        if not handle:
+            products.append(
+                _error_block(row, "(missing)", RowError(row.line_number, "Handle", "a row needs a Handle"))
+            )
+        elif not _HANDLE_RE.match(handle):
+            products.append(
+                _error_block(
+                    row,
+                    handle,
+                    RowError(
+                        row.line_number,
+                        "Handle",
+                        f"'{handle}' isn't a valid handle — lowercase letters, numbers, and dashes only",
+                    ),
+                )
+            )
+        elif handle in closed_handles:
+            products.append(
+                _error_block(
+                    row,
+                    handle,
+                    RowError(
+                        row.line_number,
+                        "Handle",
+                        f"rows for '{handle}' must be consecutive — it already appeared earlier in the file",
+                    ),
+                )
+            )
+        else:
+            block = [row]
+    flush()
+    return products
+
+
+def all_errors(products: list[CanonicalProduct]) -> list[RowError]:
+    return [error for product in products for error in product.errors]
+
+
+def _error_block(row: Row, handle: str, error: RowError) -> CanonicalProduct:
+    return CanonicalProduct(first_line=row.line_number, handle=handle, title="", errors=[error])
+
+
+def _build_block(rows: list[Row]) -> CanonicalProduct:
+    first = rows[0]
+    handle = first.cells["Handle"]
+    errors: list[RowError] = []
+
+    title = first.cells.get("Title", "")
+    if not title:
+        errors.append(RowError(first.line_number, "Title", f"'{handle}' is missing its Title"))
+
+    option_names = tuple(first.cells.get(f"Option{n} Name") or None for n in (1, 2, 3))
+    has_options = any(option_names)
+
+    # Product-level fields come from the first row only; empty cell == clear (None).
+    fields: dict[str, object] = {}
+    for column, field_name in PRODUCT_COLUMNS.items():
+        if column in _ATTRIBUTE_COLUMNS or column not in first.cells:
+            continue
+        cell = first.cells[column]
+        if not cell:
+            fields[field_name] = None
+            continue
+        value = _product_value(first.line_number, column, field_name, cell, errors)
+        if value is not _INVALID:
+            fields[field_name] = value
+
+    variants: list[CanonicalVariant] = []
+    images: list[CanonicalImage] = []
+    seen_combos: set[tuple[str | None, str | None, str | None]] = set()
+
+    for index, row in enumerate(rows):
+        cells = row.cells
+        line = row.line_number
+
+        for column in COMPONENT_COLUMNS:
+            if cells.get(column):
+                errors.append(
+                    RowError(line, column, "kits arrive in a coming release — leave the Component columns empty")
+                )
+
+        has_image = bool(cells.get("Image Src"))
+        if has_image:
+            _collect_image(row, images, errors)
+
+        # A row carries a variant iff any option value / Variant-* cell is filled;
+        # the first row of a no-option product always carries the single variant.
+        carries_variant = (
+            any(cells.get(c) for c in OPTION_VALUE_COLUMNS)
+            or any(cells.get(c) for c in VARIANT_COLUMNS)
+            or (index == 0 and not has_options)
+        )
+        if carries_variant:
+            options = tuple(cells.get(c) or None for c in OPTION_VALUE_COLUMNS)
+            for n in (1, 2, 3):
+                value, name = options[n - 1], option_names[n - 1]
+                if value and not name:
+                    errors.append(
+                        RowError(
+                            line,
+                            f"Option{n} Value",
+                            f"Option{n} Value given but the product has no Option{n} Name",
+                        )
+                    )
+                elif name and not value:
+                    errors.append(
+                        RowError(
+                            line,
+                            f"Option{n} Value",
+                            f"this variant is missing its Option{n} Value ('{name}')",
+                        )
+                    )
+            if not has_options:
+                if variants:
+                    errors.append(RowError(line, None, "a product without options can have only one variant"))
+            elif options in seen_combos:
+                errors.append(
+                    RowError(line, None, f"duplicate variant — '{handle}' already has a variant with these options")
+                )
+            seen_combos.add(options)
+
+            variant_fields: dict[str, object] = {}
+            for column, field_name in VARIANT_COLUMNS.items():
+                if column not in cells:
+                    continue
+                cell = cells[column]
+                if not cell:
+                    variant_fields[field_name] = None
+                    continue
+                value = _variant_value(line, column, field_name, cell, errors)
+                if value is _INVALID:
+                    continue
+                variant_fields[field_name] = value
+                if field_name == "variant_image" and cell not in {i.source_url for i in images}:
+                    images.append(
+                        CanonicalImage(line_number=line, source_url=cell, position=len(images) + 1, alt_text=None)
+                    )
+            variants.append(CanonicalVariant(line_number=line, options=options, fields=variant_fields))
+        elif index > 0 and not has_image:
+            errors.append(RowError(line, None, "this row has no variant or image data"))
+
+    return CanonicalProduct(
+        first_line=first.line_number,
+        handle=handle,
+        title=title,
+        option_names=option_names,
+        fields=fields,
+        variants=variants,
+        images=images,
+        errors=errors,
+    )
+
+
+def _collect_image(row: Row, images: list[CanonicalImage], errors: list[RowError]) -> None:
+    cells = row.cells
+    source_url = cells["Image Src"]
+    position_cell = cells.get("Image Position", "")
+    position: int | None = None
+    if position_cell:
+        try:
+            position = int(position_cell)
+            if position < 1:
+                raise ValueError
+        except ValueError:
+            position = None
+            errors.append(RowError(row.line_number, "Image Position", f"'{position_cell}' is not a position"))
+    # Dedupe by source URL within the block — first occurrence wins.
+    if source_url in {i.source_url for i in images}:
+        return
+    images.append(
+        CanonicalImage(
+            line_number=row.line_number,
+            source_url=source_url,
+            position=position if position is not None else len(images) + 1,
+            alt_text=cells.get("Image Alt Text") or None,
+        )
+    )
+
+
+def _product_value(line: int, column: str, field_name: str, cell: str, errors: list[RowError]) -> object:
+    if field_name == "tags":
+        return [tag.strip() for tag in cell.split(",") if tag.strip()]
+    if field_name == "status":
+        status = cell.lower()
+        if status not in _STATUSES:
+            errors.append(RowError(line, column, f"'{cell}' is not a status — use draft, active, or archived"))
+            return _INVALID
+        return status
+    if field_name == "published":
+        flag = cell.upper()
+        if flag not in ("TRUE", "FALSE"):
+            errors.append(RowError(line, column, f"'{cell}' is not TRUE or FALSE"))
+            return _INVALID
+        return flag == "TRUE"
+    if field_name == "description_html":
+        return nh3.clean(cell)
+    if field_name == "product_type":
+        if cell != "standalone":
+            errors.append(RowError(line, column, "kits arrive in a coming release — Type must be 'standalone'"))
+            return _INVALID
+        return cell
+    return cell
+
+
+def _variant_value(line: int, column: str, field_name: str, cell: str, errors: list[RowError]) -> object:
+    if field_name in ("price", "cost"):
+        return _decimal_or_error(line, column, cell, f"'{cell}' is not a price", errors)
+    if field_name in ("weight", "volume"):
+        return _decimal_or_error(line, column, cell, f"'{cell}' is not a number", errors)
+    if field_name == "inventory_qty":
+        try:
+            quantity = int(cell)
+            if quantity < 0:
+                raise ValueError
+        except ValueError:
+            errors.append(RowError(line, column, f"'{cell}' is not a whole number"))
+            return _INVALID
+        return quantity
+    if field_name == "position":
+        try:
+            position = int(cell)
+            if position < 1:
+                raise ValueError
+        except ValueError:
+            errors.append(RowError(line, column, f"'{cell}' is not a position"))
+            return _INVALID
+        return position
+    return cell
+
+
+def _decimal_or_error(line: int, column: str, cell: str, message: str, errors: list[RowError]) -> object:
+    try:
+        value = Decimal(cell)
+        if not value.is_finite() or value < 0:
+            raise InvalidOperation
+    except InvalidOperation:
+        errors.append(RowError(line, column, message))
+        return _INVALID
+    return value

backend/app/main.py

@@ -4,7 +4,8 @@ SLICE-1 mounted /healthz; SLICE-2 adds the /api/auth/* identity endpoints (§6.4
 translates HTTP <-> domain calls and owns no business logic (INV-6): every rule lives in
 the accounts domain. create_app() opens the pool, self-migrates (INV-1, INV-7), and builds
 the configured mailer (INV-8) at startup. SLICE-3 adds POST /api/storefronts and feeds the
-_storefront_for seam from the storefronts domain.
+_storefront_for seam from the storefronts domain. SLICE-5 adds the /api/products/* import
+spine (SD-0002 §6.4): each endpoint is a gate + one products-domain call + error mapping.
 """
 from __future__ import annotations
 
@@ -15,12 +16,12 @@ from pathlib import Path
 from typing import Any
 
 import psycopg
-from fastapi import Depends, FastAPI, Response
-from fastapi.responses import JSONResponse
+from fastapi import Depends, FastAPI, File, Query, Response, UploadFile
+from fastapi.responses import JSONResponse, PlainTextResponse, StreamingResponse
 from fastapi.staticfiles import StaticFiles
 from pydantic import BaseModel
 
-from app.domains import accounts, storefronts
+from app.domains import accounts, products, storefronts
 from app.platform import config, db
 from app.platform import mailer as mailer_mod
 from app.platform.deps import SESSION_COOKIE, get_conn, get_mailer, get_session
@@ -61,6 +62,26 @@ def _storefront_for(conn: psycopg.Connection, account: accounts.Account) -> dict
     return {"id": sf.id, "name": sf.name} if sf else None
 
 
+def _merchant_gate(
+    conn: psycopg.Connection, sess: dict | None
+) -> JSONResponse | tuple[accounts.Account, storefronts.Storefront]:
+    """The shared /api/products/* gate: a signed-in account that has its storefront.
+
+    Returns the (account, storefront) pair, or the ready-to-return error response —
+    401 with no session, 404 before the storefront exists (INV-14: every products
+    call is storefront-scoped, so there is nothing to address yet).
+    """
+    if sess is None:
+        return _error(401, "unauthenticated", "You are not signed in.")
+    account = accounts.get_account(conn, sess["account_id"])
+    if account is None:
+        return _error(401, "unauthenticated", "You are not signed in.")
+    sf = storefronts.storefront_for(conn, account.id)
+    if sf is None:
+        return _error(404, "no_storefront", "Create your storefront first.")
+    return account, sf
+
+
 def _ensure_app_logging() -> None:
     """Surface the app's own `ecomm.*` INFO logs on stderr (idempotent).
 
@@ -208,6 +229,181 @@ def create_app(database_url: str | None = None, static_dir: str | Path | None =
             )
         return JSONResponse(status_code=201, content={"id": sf.id, "name": sf.name})
 
+    @app.post("/api/products/imports")
+    async def import_upload(
+        file: UploadFile = File(...),
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """Upload a CSV → validated import draft (§6.4; PUC-2, PUC-5/5a on rejection)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        account, sf = gate
+        data = await file.read()
+        if len(data) > products.MAX_FILE_BYTES:
+            return _error(413, "file_too_large", "This file is larger than 10 MB.")
+        try:
+            draft = products.import_validate(conn, sf.id, account.id, file.filename or "upload.csv", data)
+        except products.FileRejected as exc:
+            return _error(400, exc.code, exc.message)
+        return JSONResponse(status_code=201, content=draft)
+
+    @app.get("/api/products/imports/drafts/{draft_id}")
+    def get_import_draft(
+        draft_id: int,
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """One draft's preview payload — summary, never the file bytes (§6.4; PUC-3)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        _account, sf = gate
+        try:
+            return products.get_draft(conn, sf.id, draft_id)
+        except products.DraftNotFound:
+            return _error(404, "not_found", "No such import preview.")
+        except products.DraftExpired:
+            return _error(410, "draft_expired", "This preview expired — upload the file again.")
+
+    @app.get("/api/products/imports/drafts/{draft_id}/records")
+    def get_import_draft_records(
+        draft_id: int,
+        kind: str | None = Query(default=None, pattern="^(add|update|unchanged|error)$"),
+        limit: int = Query(default=100, ge=1, le=500),
+        offset: int = Query(default=0, ge=0),
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """The draft's per-product preview records, paged + kind-filtered (§6.4; PUC-3)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        _account, sf = gate
+        try:
+            records = products.get_draft_records(conn, sf.id, draft_id, kind, limit, offset)
+        except products.DraftNotFound:
+            return _error(404, "not_found", "No such import preview.")
+        except products.DraftExpired:
+            return _error(410, "draft_expired", "This preview expired — upload the file again.")
+        return {"records": records}
+
+    @app.post("/api/products/imports/drafts/{draft_id}/confirm")
+    def confirm_import_draft(
+        draft_id: int,
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """Apply the previewed diff as one import run (§6.4; PUC-4, INV-10/11)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        account, sf = gate
+        try:
+            run_id = products.confirm_draft(conn, sf.id, account.id, draft_id)
+        except products.DraftNotFound:
+            return _error(404, "not_found", "No such import preview.")
+        except products.DraftExpired:
+            return _error(410, "draft_expired", "This preview expired — upload the file again.")
+        except products.PreviewStale:
+            return _error(
+                409, "preview_stale",
+                "Your catalog changed since this preview — upload the file again.",
+            )
+        except products.NothingToApply:
+            return _error(
+                409, "nothing_to_apply",
+                "Nothing to change — your catalog already matches this file.",
+            )
+        return JSONResponse(status_code=201, content={"run_id": run_id})
+
+    @app.delete("/api/products/imports/drafts/{draft_id}")
+    def discard_import_draft(
+        draft_id: int,
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """Discard the draft, no trace kept; idempotent (§6.4; PUC-3a)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        _account, sf = gate
+        products.discard_draft(conn, sf.id, draft_id)
+        return Response(status_code=204)
+
+    @app.get("/api/products/imports/runs")
+    def list_import_runs(
+        limit: int = Query(default=50, ge=1, le=200),
+        offset: int = Query(default=0, ge=0),
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """The storefront's import history, newest first (§6.4; PUC-8)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        _account, sf = gate
+        return {"runs": products.list_runs(conn, sf.id, limit, offset)}
+
+    @app.get("/api/products/imports/runs/{run_id}")
+    def get_import_run(
+        run_id: int,
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """One run's detail payload, errors included (§6.4; PUC-8)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        _account, sf = gate
+        try:
+            return products.get_run(conn, sf.id, run_id)
+        except products.RunNotFound:
+            return _error(404, "not_found", "No such import run.")
+
+    @app.get("/api/products/summary")
+    def products_summary(
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """The products dashboard counts (§6.4)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        _account, sf = gate
+        return products.summary(conn, sf.id)
+
+    @app.get("/api/products/export")
+    def export_products(
+        status: str = Query(default="all", pattern="^(all|active|draft|archived)$"),
+        conn: psycopg.Connection = Depends(get_conn),
+        sess: dict | None = Depends(get_session),
+    ):
+        """Stream the catalog as canonical CSV, optionally status-filtered (§6.4; PUC-9)."""
+        gate = _merchant_gate(conn, sess)
+        if isinstance(gate, JSONResponse):
+            return gate
+        _account, sf = gate
+        try:
+            stream = products.export_catalog(conn, sf.id, status)
+        except products.EmptyCatalog:
+            return _error(409, "empty_catalog", "There are no products to export.")
+        return StreamingResponse(
+            stream,
+            media_type="text/csv",
+            headers={"content-disposition": 'attachment; filename="ecomm-products-export.csv"'},
+        )
+
+    @app.get("/api/products/sample.csv")
+    def products_sample_csv():
+        """The DOC-3 worked-example CSV. Documentation, so no auth gate (§6.4)."""
+        return PlainTextResponse(
+            products.SAMPLE_CSV_PATH.read_text(),
+            media_type="text/csv",
+            headers={"content-disposition": 'attachment; filename="ecomm-products-sample.csv"'},
+        )
+
     # Deployed topology (launch-app SPEC §2): nginx proxies everything here, so the
     # backend serves the built SPA. Mounted LAST so /healthz and /api/* win. In dev the
     # dist dir doesn't exist (Vite serves the frontend) and the mount is skipped.

backend/app/platform/telemetry.py

@@ -0,0 +1,13 @@
+"""Structured log-event telemetry (SD-0002 §9.1). One JSON object per event on the
+`ecomm.telemetry` logger — counts and durations only; never file names, URLs,
+catalog content, or secret bytes (§6.3-handbook)."""
+from __future__ import annotations
+
+import json
+import logging
+
+_logger = logging.getLogger("ecomm.telemetry")
+
+
+def emit(event: str, **fields: object) -> None:
+    _logger.info(json.dumps({"event": event, **fields}, sort_keys=True, default=str))

backend/migrations/0002_products.sql

@@ -0,0 +1,130 @@
+-- 0002_products.sql — SD-0002 §6.3 data model (SLICE-5). Forward-only (INV-7):
+-- never edit once merged; add a new numbered migration.
+
+-- product — one catalog product per (storefront, handle) (INV-13/14). Option *names*
+-- live here; product_type's kit values are schema-open but a service-layer rule
+-- rejects non-'standalone' until #15 (same pattern as INV-4).
+CREATE TABLE product (
+    id            BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+    storefront_id BIGINT NOT NULL REFERENCES storefront (id),
+    handle        TEXT NOT NULL,
+    title         TEXT NOT NULL,
+    description_html TEXT,
+    vendor        TEXT,
+    product_type  TEXT NOT NULL DEFAULT 'standalone'
+                  CHECK (product_type IN ('standalone', 'kit_virtual', 'kit_assembled')),
+    google_product_category TEXT,
+    tags          TEXT[] NOT NULL DEFAULT '{}',
+    status        TEXT NOT NULL DEFAULT 'active' CHECK (status IN ('draft', 'active', 'archived')),
+    published     BOOLEAN NOT NULL DEFAULT TRUE,
+    option1_name  TEXT,
+    option2_name  TEXT,
+    option3_name  TEXT,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at    TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+CREATE UNIQUE INDEX product_handle_key ON product (storefront_id, handle);  -- INV-13
+
+-- variant — one purchasable form, identified by its option-value combo (INV-13).
+-- SKU is indexed data, never identity. image_id FK is added after product_image.
+CREATE TABLE variant (
+    id            BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+    product_id    BIGINT NOT NULL REFERENCES product (id),
+    position      INTEGER NOT NULL,
+    option1_value TEXT,
+    option2_value TEXT,
+    option3_value TEXT,
+    sku           TEXT,
+    barcode       TEXT,
+    price         NUMERIC,
+    cost          NUMERIC,
+    weight        NUMERIC,
+    weight_unit   TEXT,
+    volume        NUMERIC,
+    volume_unit   TEXT,
+    tax_id_1      TEXT,
+    tax_id_2      TEXT,
+    inventory_tracker TEXT,
+    inventory_qty INTEGER,
+    image_id      BIGINT,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at    TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+-- Postgres 16 (compose + Cloud SQL pin): NULLS NOT DISTINCT makes the all-NULL
+-- no-option combo unique too (INV-13).
+CREATE UNIQUE INDEX variant_option_combo_key
+    ON variant (product_id, option1_value, option2_value, option3_value)
+    NULLS NOT DISTINCT;
+CREATE INDEX variant_sku_idx ON variant (sku);
+
+-- product_image — identity within a product is source_url (§6.3); bytes live in
+-- object storage from SLICE-7 (keys nullable until fetched). status starts 'pending';
+-- SLICE-5 stubs the fetch phase so rows simply stay pending.
+CREATE TABLE product_image (
+    id            BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+    product_id    BIGINT NOT NULL REFERENCES product (id),
+    position      INTEGER NOT NULL,
+    source_url    TEXT NOT NULL,
+    alt_text      TEXT,
+    status        TEXT NOT NULL DEFAULT 'pending'
+                  CHECK (status IN ('pending', 'fetched', 'rejected_low_res', 'rejected_not_image', 'failed')),
+    failure_reason TEXT,
+    key_original  TEXT,
+    key_thumb     TEXT,
+    key_card      TEXT,
+    key_detail    TEXT,
+    import_run_id BIGINT,
+    fetched_at    TIMESTAMPTZ,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+CREATE UNIQUE INDEX product_image_src_key ON product_image (product_id, source_url);
+ALTER TABLE variant
+    ADD CONSTRAINT variant_image_fk FOREIGN KEY (image_id) REFERENCES product_image (id);
+
+-- import_draft — the preview's server side (INV-11). file_bytes is the SLICE-5
+-- interim home for the upload (objectstore key from SLICE-7). Deleted outright on
+-- cancel/expiry — drafts never appear in history (PUC-3a).
+CREATE TABLE import_draft (
+    id            BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+    storefront_id BIGINT NOT NULL REFERENCES storefront (id),
+    account_id    BIGINT NOT NULL REFERENCES account (id),
+    file_name     TEXT NOT NULL,
+    dialect       TEXT NOT NULL,
+    file_bytes    BYTEA NOT NULL,
+    summary       JSONB NOT NULL,
+    records       JSONB NOT NULL,
+    fingerprint   TEXT NOT NULL,
+    unknown_columns TEXT[] NOT NULL DEFAULT '{}',
+    expires_at    TIMESTAMPTZ NOT NULL,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+-- import_run — the durable record of one confirmed import (PUC-8); created only at
+-- confirm (PUC-4).
+CREATE TABLE import_run (
+    id            BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+    storefront_id BIGINT NOT NULL REFERENCES storefront (id),
+    account_id    BIGINT NOT NULL REFERENCES account (id),
+    file_name     TEXT NOT NULL,
+    dialect       TEXT NOT NULL,
+    products_added   INTEGER NOT NULL,
+    products_updated INTEGER NOT NULL,
+    rows_errored     INTEGER NOT NULL,
+    status        TEXT NOT NULL
+                  CHECK (status IN ('applying', 'fetching_images', 'complete', 'complete_with_problems')),
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
+    completed_at  TIMESTAMPTZ
+);
+CREATE INDEX import_run_history_idx ON import_run (storefront_id, created_at DESC);
+
+-- import_run_error — one row per rejected CSV row (PUC-5), merchant-language message.
+CREATE TABLE import_run_error (
+    id          BIGINT GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
+    run_id      BIGINT NOT NULL REFERENCES import_run (id),
+    line_number INTEGER NOT NULL,
+    column_name TEXT,
+    message     TEXT NOT NULL
+);
+
+ALTER TABLE product_image
+    ADD CONSTRAINT product_image_run_fk FOREIGN KEY (import_run_id) REFERENCES import_run (id);

backend/requirements.txt

@@ -5,3 +5,5 @@ psycopg[binary]>=3.1
 psycopg-pool>=3.2
 pytest>=8.0
 import-linter>=2.0
+nh3>=0.2
+python-multipart>=0.0.9

backend/tests/test_migrations.py

@@ -1,4 +1,5 @@
 import psycopg
+import pytest
 
 from app.platform import db
 
@@ -12,10 +13,10 @@ def _table_names(conn) -> set[str]:
     return {r[0] for r in rows}
 
 
-def test_migrate_from_empty_applies_0001(fresh_db_url):
+def test_migrate_from_empty_applies_all(fresh_db_url):
     with psycopg.connect(fresh_db_url) as conn:
         applied = db.migrate(conn)
-    assert applied == ["0001_init.sql"]
+    assert applied == ["0001_init.sql", "0002_products.sql"]
     with psycopg.connect(fresh_db_url) as conn:
         assert _TABLES.issubset(_table_names(conn))
 
@@ -41,3 +42,24 @@ def test_membership_has_no_unique_account_constraint(fresh_db_url):
         ).fetchall()
     defs = " ".join(r[0] for r in rows).lower()
     assert "unique" not in defs.replace("primary key", "") or "(account_id)" not in defs
+
+
+def test_0002_products_tables_exist(fresh_db_url):
+    with psycopg.connect(fresh_db_url) as conn:
+        db.migrate(conn)
+        for table in ("product", "variant", "product_image", "import_draft", "import_run", "import_run_error"):
+            assert conn.execute("SELECT to_regclass(%s)", (f"public.{table}",)).fetchone()[0] == table
+
+
+def test_0002_variant_option_combo_unique_treats_nulls_as_equal(fresh_db_url):
+    # INV-13: the no-option product's single variant has NULL option values; a second
+    # all-NULL combo must collide (NULLS NOT DISTINCT).
+    with psycopg.connect(fresh_db_url) as conn:
+        db.migrate(conn)
+        sf = conn.execute("INSERT INTO storefront (name) VALUES ('s') RETURNING id").fetchone()[0]
+        pid = conn.execute(
+            "INSERT INTO product (storefront_id, handle, title) VALUES (%s,'h','T') RETURNING id", (sf,)
+        ).fetchone()[0]
+        conn.execute("INSERT INTO variant (product_id, position) VALUES (%s, 1)", (pid,))
+        with pytest.raises(psycopg.errors.UniqueViolation):
+            conn.execute("INSERT INTO variant (product_id, position) VALUES (%s, 2)", (pid,))

backend/tests/test_products_codec.py

@@ -0,0 +1,69 @@
+"""§6.5.1 file-level codec — parse, caps, required columns (PUC-5a fixtures)."""
+import pytest
+
+from app.domains.products import FileRejected
+from app.domains.products.codec import parse_csv
+
+
+def _csv(*lines: str) -> bytes:
+    return ("\n".join(lines) + "\n").encode()
+
+
+GOOD = _csv(
+    "Handle,Title,Variant Price,Bogus Column",
+    "moon-mug,Moon Mug,18.00,x",
+    "star-tee,Star Tee,24.00,y",
+)
+
+
+def test_parses_header_rows_and_unknown_columns():
+    parsed = parse_csv(GOOD)
+    assert parsed.dialect == "canonical"
+    assert parsed.unknown_columns == ["Bogus Column"]
+    assert [r.line_number for r in parsed.rows] == [2, 3]
+    assert parsed.rows[0].cells["Handle"] == "moon-mug"
+    assert parsed.rows[0].cells["Variant Price"] == "18.00"
+    assert "Bogus Column" not in parsed.rows[0].cells
+
+
+def test_bom_tolerated():
+    parsed = parse_csv(b"\xef\xbb\xbf" + GOOD)
+    assert parsed.rows[0].cells["Handle"] == "moon-mug"
+
+
+def test_quoted_cells_rfc4180():
+    parsed = parse_csv(_csv("Handle,Title,Tags", 'mug,"The ""Best"" Mug","a, b"'))
+    assert parsed.rows[0].cells["Title"] == 'The "Best" Mug'
+    assert parsed.rows[0].cells["Tags"] == "a, b"
+
+
+def test_empty_rows_skipped_short_rows_padded():
+    parsed = parse_csv(_csv("Handle,Title,Vendor", "mug,Mug", "", ",,", "tee,Tee,Acme"))
+    assert [r.cells["Handle"] for r in parsed.rows] == ["mug", "tee"]
+    assert parsed.rows[0].cells["Vendor"] == ""
+
+
+@pytest.mark.parametrize(
+    "data,code",
+    [
+        (b"\xff\xfe\x00garbage\x00", "not_csv"),
+        (b"", "not_csv"),
+        (_csv("Title,Vendor", "Mug,Acme"), "missing_required_column"),
+        (_csv("Handle,Vendor", "mug,Acme"), "missing_required_column"),
+        (
+            _csv("Handle,Title", *(f"h{i},T{i}" for i in range(5001))),
+            "too_many_rows",
+        ),
+        (b"Handle,Title\n" + b"x" * (10 * 1024 * 1024), "file_too_large"),
+    ],
+)
+def test_file_level_rejections(data, code):
+    with pytest.raises(FileRejected) as exc:
+        parse_csv(data)
+    assert exc.value.code == code
+
+
+def test_missing_column_message_names_the_column():
+    with pytest.raises(FileRejected) as exc:
+        parse_csv(_csv("Handle,Vendor", "mug,Acme"))
+    assert "'Title'" in exc.value.message

backend/tests/test_products_diff.py

@@ -0,0 +1,146 @@
+"""Diff engine — classification, blank-vs-absent, option matching, fingerprint (§6.8)."""
+from decimal import Decimal
+
+from app.domains.products.codec import parse_csv
+from app.domains.products.diff import (
+    CatalogImage, CatalogProduct, CatalogVariant, compute_diff,
+)
+from app.domains.products.validate import build_products
+
+
+def _canon(*lines: str):
+    return build_products(parse_csv(("\n".join(lines) + "\n").encode()))
+
+
+def _catalog_mug(**overrides):
+    fields = {
+        "title": "Moon Mug", "description_html": None, "vendor": "Acme",
+        "product_type": "standalone", "google_product_category": None,
+        "tags": ["kitchen"], "status": "active", "published": True,
+    } | overrides
+    return {
+        "moon-mug": CatalogProduct(
+            id=1, handle="moon-mug", title=fields["title"],
+            option_names=(None, None, None), fields=fields,
+            variants=[CatalogVariant(id=10, options=(None, None, None), position=1,
+                                     fields={"sku": "SKU-1", "barcode": None, "price": Decimal("18.00"),
+                                             "cost": None, "weight": None, "weight_unit": None,
+                                             "volume": None, "volume_unit": None, "tax_id_1": None,
+                                             "tax_id_2": None, "inventory_tracker": None,
+                                             "inventory_qty": 40, "variant_image": None})],
+            images=[CatalogImage(id=100, source_url="https://x/a.jpg", position=1, alt_text=None)],
+        )
+    }
+
+
+HEADER = "Handle,Title,Vendor,Tags,Status,Variant SKU,Variant Price,Variant Inventory Qty,Image Src"
+MUG_ROW = 'moon-mug,Moon Mug,Acme,kitchen,active,SKU-1,18.00,40,https://x/a.jpg'
+
+
+def test_new_handle_classifies_add():
+    diff = compute_diff({}, _canon(HEADER, MUG_ROW))
+    [rec] = diff.records
+    assert rec["kind"] == "add" and rec["handle"] == "moon-mug" and rec["variant_count"] == 1
+    assert diff.summary == {"adds": 1, "updates": 0, "unchanged": 0, "errors": 0}
+    assert rec["detail"]["set"]["status"] == "active"
+
+
+def test_identical_file_classifies_unchanged():
+    diff = compute_diff(_catalog_mug(), _canon(HEADER, MUG_ROW))
+    assert diff.records[0]["kind"] == "unchanged"
+    assert diff.summary["unchanged"] == 1
+
+
+def test_changed_price_classifies_update_with_before_after():
+    row = MUG_ROW.replace("18.00", "21.00")
+    diff = compute_diff(_catalog_mug(), _canon(HEADER, row))
+    [rec] = diff.records
+    assert rec["kind"] == "update"
+    [vchange] = rec["detail"]["variants"]
+    assert {"field": "price", "before": "18.00", "after": "21.00"} in vchange["changes"]
+
+
+def test_absent_column_untouched_empty_cell_clears():
+    # Vendor column absent: vendor stays Acme. Status present-but-empty: clears to default 'active' (already active -> no change).
+    diff = compute_diff(
+        _catalog_mug(),
+        _canon("Handle,Title,Status,Variant SKU,Variant Price,Variant Inventory Qty,Image Src",
+               "moon-mug,Moon Mug,,SKU-1,18.00,40,https://x/a.jpg"),
+    )
+    assert diff.records[0]["kind"] == "unchanged"
+
+
+def test_empty_cell_clear_shows_in_diff():
+    # Vendor present-but-empty clears Acme -> None: an explicit, previewable change (§6.5.1).
+    diff = compute_diff(
+        _catalog_mug(),
+        _canon("Handle,Title,Vendor,Variant SKU,Variant Price,Variant Inventory Qty,Image Src",
+               "moon-mug,Moon Mug,,SKU-1,18.00,40,https://x/a.jpg"),
+    )
+    [rec] = diff.records
+    assert rec["kind"] == "update"
+    assert {"field": "vendor", "before": "Acme", "after": None} in rec["detail"]["changes"]
+
+
+def test_new_option_combo_is_variant_add_existing_untouched():
+    catalog = _catalog_mug()
+    diff = compute_diff(
+        catalog,
+        _canon("Handle,Title,Option1 Name,Option1 Value,Variant Price",
+               "moon-mug,Moon Mug,Size,Large,25.00"),
+    )
+    [rec] = diff.records
+    assert rec["kind"] == "update"
+    kinds = [v.get("kind") for v in rec["detail"]["variants"]]
+    assert "add" in kinds
+
+
+POSITION_HEADER = HEADER + ",Variant Position"
+
+
+def test_matching_variant_position_column_classifies_unchanged():
+    # position is an attribute on CatalogVariant (not in fields{}); the compare
+    # must read it from there, not invent a before:None.
+    diff = compute_diff(_catalog_mug(), _canon(POSITION_HEADER, MUG_ROW + ",1"))
+    assert diff.records[0]["kind"] == "unchanged"
+
+
+def test_changed_variant_position_reports_honest_before():
+    diff = compute_diff(_catalog_mug(), _canon(POSITION_HEADER, MUG_ROW + ",2"))
+    [rec] = diff.records
+    assert rec["kind"] == "update"
+    [ventry] = rec["detail"]["variants"]
+    assert {"field": "position", "before": 1, "after": 2} in ventry["changes"]
+
+
+def test_blank_position_cell_resolves_to_file_order_unchanged():
+    # A present-but-empty Variant Position cell resets to file order (the spec's
+    # "defaults to file order"), never to NULL — here file order matches the
+    # catalog position, so nothing changes.
+    diff = compute_diff(_catalog_mug(), _canon(POSITION_HEADER, MUG_ROW + ","))
+    assert diff.records[0]["kind"] == "unchanged"
+
+
+def test_blank_position_cell_updates_to_file_order():
+    catalog = _catalog_mug()
+    catalog["moon-mug"].variants[0].position = 2
+    diff = compute_diff(catalog, _canon(POSITION_HEADER, MUG_ROW + ","))
+    [rec] = diff.records
+    assert rec["kind"] == "update"
+    [ventry] = rec["detail"]["variants"]
+    assert {"field": "position", "before": 2, "after": 1} in ventry["changes"]
+
+
+def test_error_product_classifies_error():
+    diff = compute_diff({}, _canon("Handle,Title,Variant Price", "mug,Mug,nope"))
+    [rec] = diff.records
+    assert rec["kind"] == "error"
+    assert rec["detail"]["errors"][0]["column"] == "Variant Price"
+
+
+def test_fingerprint_stable_and_drift_sensitive():
+    d1 = compute_diff(_catalog_mug(), _canon(HEADER, MUG_ROW))
+    d2 = compute_diff(_catalog_mug(), _canon(HEADER, MUG_ROW))
+    d3 = compute_diff(_catalog_mug(title="Renamed"), _canon(HEADER, MUG_ROW))
+    assert d1.fingerprint == d2.fingerprint
+    assert d1.fingerprint != d3.fingerprint

backend/tests/test_products_endpoints.py

@@ -0,0 +1,135 @@
+"""§6.4 /api/products/* endpoint scenarios (PUC-2/3/3a/4/5/5a/8 + gates)."""
+import io
+import re
+from contextlib import contextmanager
+
+from fastapi.testclient import TestClient
+
+from app.main import create_app
+
+GOOD_CSV = b"Handle,Title,Vendor,Variant Price\nmoon-mug,Moon Mug,Acme,18.00\n"
+
+
+@contextmanager
+def _merchant_client(fresh_db_url, email="m@example.com"):
+    with TestClient(create_app(database_url=fresh_db_url)) as client:
+        client.post("/api/auth/request-code", json={"email": email})
+        code = re.search(r"\b(\d{6})\b", client.app.state.mailer.outbox[-1].body).group(1)
+        client.post("/api/auth/verify", json={"email": email, "code": code})
+        client.post("/api/storefronts", json={})
+        yield client
+
+
+def _upload(client, data=GOOD_CSV, name="cat.csv"):
+    return client.post("/api/products/imports", files={"file": (name, io.BytesIO(data), "text/csv")})
+
+
+def test_upload_returns_201_draft(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        resp = _upload(client)
+        assert resp.status_code == 201
+        body = resp.json()
+        assert body["summary"]["adds"] == 1 and body["dialect"] == "canonical"
+
+
+def test_upload_rejections_carry_codes(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        resp = _upload(client, b"Vendor\nAcme\n")
+        assert resp.status_code == 400
+        assert resp.json()["error"]["code"] == "missing_required_column"
+        resp = _upload(client, b"Handle,Title\n" + b"x" * (10 * 1024 * 1024 + 1))
+        assert resp.status_code == 413
+
+
+def test_unauthenticated_401_and_no_storefront_404(fresh_db_url):
+    with TestClient(create_app(database_url=fresh_db_url)) as client:
+        assert _upload(client).status_code == 401
+        client.post("/api/auth/request-code", json={"email": "x@example.com"})
+        code = re.search(r"\b(\d{6})\b", client.app.state.mailer.outbox[-1].body).group(1)
+        client.post("/api/auth/verify", json={"email": "x@example.com", "code": code})
+        assert _upload(client).status_code == 404
+
+
+def test_preview_confirm_run_flow(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        draft = _upload(client).json()
+        recs = client.get(f"/api/products/imports/drafts/{draft['id']}/records").json()["records"]
+        assert recs[0]["kind"] == "add"
+        run_id = client.post(f"/api/products/imports/drafts/{draft['id']}/confirm").json()["run_id"]
+        run = client.get(f"/api/products/imports/runs/{run_id}").json()
+        assert run["products_added"] == 1 and run["by"] == "m@example.com"
+        assert client.get("/api/products/summary").json()["product_count"] == 1
+        assert client.get("/api/products/imports/runs").json()["runs"][0]["id"] == run_id
+
+
+def test_cancel_no_trace_puc3a(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        draft = _upload(client).json()
+        assert client.delete(f"/api/products/imports/drafts/{draft['id']}").status_code == 204
+        assert client.get(f"/api/products/imports/drafts/{draft['id']}").status_code == 404
+        assert client.get("/api/products/imports/runs").json()["runs"] == []
+
+
+def test_confirm_conflicts(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        d1 = _upload(client).json()
+        client.post(f"/api/products/imports/drafts/{d1['id']}/confirm")
+        d2 = _upload(client).json()
+        resp = client.post(f"/api/products/imports/drafts/{d2['id']}/confirm")
+        assert resp.status_code == 409 and resp.json()["error"]["code"] == "nothing_to_apply"
+
+
+def test_sample_csv_served(fresh_db_url):
+    with TestClient(create_app(database_url=fresh_db_url)) as client:
+        resp = client.get("/api/products/sample.csv")
+        assert resp.status_code == 200
+        assert resp.headers["content-type"].startswith("text/csv")
+        assert resp.text.startswith("Handle,Title,")
+
+
+def test_sample_csv_imports_clean(fresh_db_url):
+    """DOC-3 honesty: our own sample must validate with zero errors."""
+    with _merchant_client(fresh_db_url) as client:
+        sample = client.get("/api/products/sample.csv").content
+        body = _upload(client, sample, "sample.csv").json()
+        assert body["summary"]["errors"] == 0 and body["summary"]["adds"] == 2
+
+
+def test_export_returns_canonical_csv(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        draft = _upload(client).json()
+        client.post(f"/api/products/imports/drafts/{draft['id']}/confirm")
+        resp = client.get("/api/products/export")
+        assert resp.status_code == 200
+        assert resp.headers["content-type"].startswith("text/csv")
+        assert "attachment" in resp.headers["content-disposition"]
+        body = resp.text
+        assert body.splitlines()[0].startswith("Handle,")
+        assert "moon-mug" in body
+
+
+def test_export_status_filter_respected(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        # GOOD_CSV's moon-mug has no Status column → defaults to active.
+        draft = _upload(client).json()
+        client.post(f"/api/products/imports/drafts/{draft['id']}/confirm")
+        assert "moon-mug" in client.get("/api/products/export?status=active").text
+        # No archived products → 409.
+        assert client.get("/api/products/export?status=archived").status_code == 409
+
+
+def test_export_empty_catalog_409(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        resp = client.get("/api/products/export")
+        assert resp.status_code == 409
+        assert resp.json()["error"]["code"] == "empty_catalog"
+
+
+def test_export_requires_merchant(fresh_db_url):
+    with TestClient(create_app(database_url=fresh_db_url)) as client:
+        assert client.get("/api/products/export").status_code == 401
+
+
+def test_export_bad_status_422(fresh_db_url):
+    with _merchant_client(fresh_db_url) as client:
+        assert client.get("/api/products/export?status=bogus").status_code == 422

backend/tests/test_products_export.py

@@ -0,0 +1,100 @@
+"""Export: status-filtered catalog snapshot + the streamed service (PUC-9, TEL-3)."""
+import csv
+import io
+import json
+import logging
+
+import psycopg
+import pytest
+
+from app.domains import products
+from app.domains.products import repo
+from app.platform import db
+
+CSV = (
+    b"Handle,Title,Vendor,Status,Variant Price\n"
+    b"active-mug,Active Mug,Acme,active,18.00\n"
+    b"draft-tee,Draft Tee,Acme,draft,24.00\n"
+)
+
+
+@pytest.fixture()
+def migrated_conn(fresh_db_url):
+    with psycopg.connect(fresh_db_url) as conn:
+        db.migrate(conn)
+        yield conn
+
+
+@pytest.fixture()
+def merchant(migrated_conn):
+    acct = migrated_conn.execute(
+        "INSERT INTO account (email) VALUES ('m@example.com') RETURNING id").fetchone()[0]
+    sf = migrated_conn.execute(
+        "INSERT INTO storefront (name) VALUES ('Shop') RETURNING id").fetchone()[0]
+    migrated_conn.execute(
+        "INSERT INTO storefront_membership (account_id, storefront_id) VALUES (%s,%s)", (acct, sf))
+    migrated_conn.commit()
+    return {"account_id": acct, "storefront_id": sf}
+
+
+def _seed(conn, merchant):
+    draft = products.import_validate(conn, merchant["storefront_id"], merchant["account_id"], "c.csv", CSV)
+    products.confirm_draft(conn, merchant["storefront_id"], merchant["account_id"], draft["id"])
+
+
+def test_export_all_returns_both(migrated_conn, merchant):
+    _seed(migrated_conn, merchant)
+    snap = repo.export_catalog(migrated_conn, merchant["storefront_id"], "all")
+    assert {p.handle for p in snap} == {"active-mug", "draft-tee"}
+
+
+def test_export_status_filter(migrated_conn, merchant):
+    _seed(migrated_conn, merchant)
+    active = repo.export_catalog(migrated_conn, merchant["storefront_id"], "active")
+    assert [p.handle for p in active] == ["active-mug"]
+    draft = repo.export_catalog(migrated_conn, merchant["storefront_id"], "draft")
+    assert [p.handle for p in draft] == ["draft-tee"]
+
+
+@pytest.fixture()
+def telemetry_propagation():
+    """create_app() sets propagate=False on the parent "ecomm" logger
+    (main._ensure_app_logging), which hides ecomm.telemetry records from caplog's
+    root-logger handler whenever an API test ran first. Restore propagation here."""
+    lg = logging.getLogger("ecomm")
+    prior = lg.propagate
+    lg.propagate = True
+    yield
+    lg.propagate = prior
+
+
+def test_export_streams_canonical_csv(migrated_conn, merchant):
+    _seed(migrated_conn, merchant)
+    text = "".join(products.export_catalog(migrated_conn, merchant["storefront_id"], "all"))
+    rows = list(csv.DictReader(io.StringIO(text)))
+    assert {r["Handle"] for r in rows} == {"active-mug", "draft-tee"}
+    assert rows[0]["Handle"] == "active-mug"  # sorted by handle
+
+
+def test_export_empty_raises(migrated_conn, merchant):
+    # No catalog at all → empty.
+    with pytest.raises(products.EmptyCatalog):
+        list(products.export_catalog(migrated_conn, merchant["storefront_id"], "all"))
+
+
+def test_export_empty_after_filter_raises(migrated_conn, merchant):
+    _seed(migrated_conn, merchant)  # only active + draft exist
+    with pytest.raises(products.EmptyCatalog):
+        list(products.export_catalog(migrated_conn, merchant["storefront_id"], "archived"))
+
+
+def test_tel3_emitted(migrated_conn, merchant, caplog, telemetry_propagation):
+    _seed(migrated_conn, merchant)
+    with caplog.at_level(logging.INFO, logger="ecomm.telemetry"):
+        list(products.export_catalog(migrated_conn, merchant["storefront_id"], "all"))
+    events = [json.loads(r.message) for r in caplog.records if r.name == "ecomm.telemetry"]
+    exported = [e for e in events if e["event"] == "catalog_exported"]
+    assert len(exported) == 1
+    assert exported[0]["product_count"] == 2
+    assert exported[0]["status_filter"] == "all"
+    assert "duration_ms" in exported[0]

backend/tests/test_products_invariants.py

@@ -0,0 +1,79 @@
+"""SD-0002 invariants: INV-10 (never deletes), INV-14 (two-storefront zero bleed),
+apply transactionality (§6.8), TEL-6."""
+import json
+import logging
+
+import psycopg
+import pytest
+
+from app.domains import products
+from app.domains.products import repo, service
+from app.platform import db
+
+CSV_A = b"Handle,Title,Variant Price\nmug,Mug,10.00\ntee,Tee,20.00\n"
+CSV_PARTIAL = b"Handle,Title,Variant Price\nmug,Mug,12.00\n"
+
+
+@pytest.fixture()
+def migrated_conn(fresh_db_url):
+    with psycopg.connect(fresh_db_url) as conn:
+        db.migrate(conn)
+        yield conn
+
+
+def _merchant(conn, email="m@example.com", shop="Shop"):
+    acct = conn.execute("INSERT INTO account (email) VALUES (%s) RETURNING id", (email,)).fetchone()[0]
+    sf = conn.execute("INSERT INTO storefront (name) VALUES (%s) RETURNING id", (shop,)).fetchone()[0]
+    conn.execute("INSERT INTO storefront_membership (account_id, storefront_id) VALUES (%s,%s)", (acct, sf))
+    conn.commit()
+    return acct, sf
+
+
+def _import(conn, acct, sf, data):
+    d = products.import_validate(conn, sf, acct, "f.csv", data)
+    return products.confirm_draft(conn, sf, acct, d["id"])
+
+
+def test_inv10_partial_file_never_deletes(migrated_conn):
+    acct, sf = _merchant(migrated_conn)
+    _import(migrated_conn, acct, sf, CSV_A)
+    before = migrated_conn.execute("SELECT count(*) FROM product").fetchone()[0]
+    _import(migrated_conn, acct, sf, CSV_PARTIAL)
+    after = migrated_conn.execute("SELECT count(*) FROM product").fetchone()[0]
+    assert after >= before == 2
+
+
+def test_inv14_two_storefronts_zero_bleed(migrated_conn):
+    acct1, sf1 = _merchant(migrated_conn)
+    acct2, sf2 = _merchant(migrated_conn, "n@example.com", "Other")
+    _import(migrated_conn, acct1, sf1, CSV_A)
+    assert products.summary(migrated_conn, sf2)["product_count"] == 0
+    assert products.list_runs(migrated_conn, sf2) == []
+    _import(migrated_conn, acct2, sf2, CSV_A)
+    assert products.summary(migrated_conn, sf2)["product_count"] == 2
+    run1 = products.list_runs(migrated_conn, sf1)[0]
+    with pytest.raises(products.RunNotFound):
+        products.get_run(migrated_conn, sf2, run1["id"])
+
+
+def test_apply_failure_rolls_back_whole_transaction_tel6(migrated_conn, monkeypatch, caplog):
+    acct, sf = _merchant(migrated_conn)
+    d = products.import_validate(migrated_conn, sf, acct, "f.csv", CSV_A)
+
+    def boom(*a, **k):
+        raise RuntimeError("mid-apply crash")
+    monkeypatch.setattr(service.repo, "insert_run_errors", boom)
+    lg = logging.getLogger("ecomm")
+    prior = lg.propagate
+    lg.propagate = True
+    try:
+        with caplog.at_level(logging.INFO, logger="ecomm.telemetry"):
+            with pytest.raises(RuntimeError):
+                products.confirm_draft(migrated_conn, sf, acct, d["id"])
+    finally:
+        lg.propagate = prior
+    assert migrated_conn.execute("SELECT count(*) FROM product").fetchone()[0] == 0
+    assert migrated_conn.execute("SELECT count(*) FROM import_run").fetchone()[0] == 0
+    assert migrated_conn.execute("SELECT count(*) FROM import_draft").fetchone()[0] == 1
+    events = [json.loads(r.message) for r in caplog.records if r.name == "ecomm.telemetry"]
+    assert any(e["event"] == "import_apply_failed" and e["error_class"] == "RuntimeError" for e in events)

backend/tests/test_products_serialize.py

@@ -0,0 +1,224 @@
+"""Canonical serializer + INV-12 round-trip lock (SD-0002 §6.5.5, §6.8)."""
+import csv
+import io
+
+from app.domains.products import serialize
+from app.domains.products.diff import CatalogImage, CatalogProduct, CatalogVariant
+
+
+def _product(**kw) -> CatalogProduct:
+    """A minimal no-option catalog product (one all-NULL variant)."""
+    base = dict(
+        id=1, handle="moon-mug", title="Moon Mug",
+        option_names=(None, None, None),
+        fields={
+            "title": "Moon Mug", "description_html": None, "vendor": "Acme",
+            "product_type": "standalone", "google_product_category": None,
+            "tags": [], "status": "active", "published": True,
+        },
+        variants=[CatalogVariant(
+            id=1, options=(None, None, None), position=1,
+            fields={"sku": "WG-MUG", "barcode": None, "price": None, "cost": None,
+                    "weight": None, "weight_unit": None, "volume": None,
+                    "volume_unit": None, "tax_id_1": None, "tax_id_2": None,
+                    "inventory_tracker": None, "inventory_qty": None,
+                    "variant_image": None})],
+        images=[],
+    )
+    base.update(kw)
+    return CatalogProduct(**base)
+
+
+def _rows(products) -> list[dict]:
+    text = "".join(serialize.catalog_to_csv(products))
+    return list(csv.DictReader(io.StringIO(text)))
+
+
+def test_header_is_full_canonical_set():
+    text = "".join(serialize.catalog_to_csv([_product()]))
+    header = next(csv.reader(io.StringIO(text)))
+    # Handle + Title first; every known column present exactly once.
+    assert header[0] == "Handle"
+    assert "Title" in header and "Variant SKU" in header and "Image Src" in header
+    assert len(header) == len(set(header))
+
+
+def test_single_no_option_product_one_row():
+    rows = _rows([_product()])
+    assert len(rows) == 1
+    assert rows[0]["Handle"] == "moon-mug"
+    assert rows[0]["Title"] == "Moon Mug"
+    assert rows[0]["Variant SKU"] == "WG-MUG"
+    # A no-option product emits no option values.
+    assert rows[0]["Option1 Value"] == ""
+
+
+def _star_tee() -> CatalogProduct:
+    """A 3-variant, 2-image product (the sample.csv shape)."""
+    return CatalogProduct(
+        id=2, handle="star-tee", title="Star Tee",
+        option_names=("Size", "Color", None),
+        fields={"title": "Star Tee", "description_html": None, "vendor": "Acme",
+                "product_type": "standalone", "google_product_category": None,
+                "tags": ["apparel", "tees"], "status": "active", "published": True},
+        variants=[
+            CatalogVariant(id=10, options=("S", "Indigo", None), position=1,
+                           fields={"sku": "WG-TEE-S", "variant_image": None}),
+            CatalogVariant(id=11, options=("M", "Indigo", None), position=2,
+                           fields={"sku": "WG-TEE-M", "variant_image": None}),
+            CatalogVariant(id=12, options=("L", "Indigo", None), position=3,
+                           fields={"sku": "WG-TEE-L", "variant_image": None}),
+        ],
+        images=[
+            CatalogImage(id=1, source_url="https://x/a.jpg", position=1, alt_text="front"),
+            CatalogImage(id=2, source_url="https://x/b.jpg", position=2, alt_text="back"),
+        ],
+    )
+
+
+def test_multivariant_with_images_interleaves():
+    rows = _rows([_star_tee()])
+    assert len(rows) == 3  # max(3 variants, 2 images)
+    # Product-level fields only on the first row.
+    assert rows[0]["Title"] == "Star Tee" and rows[1]["Title"] == ""
+    assert rows[0]["Tags"] == "apparel, tees" and rows[1]["Tags"] == ""
+    # Option names on row 0; option values on every variant row.
+    assert rows[0]["Option1 Name"] == "Size" and rows[1]["Option1 Name"] == ""
+    assert [r["Option1 Value"] for r in rows] == ["S", "M", "L"]
+    assert [r["Variant SKU"] for r in rows] == ["WG-TEE-S", "WG-TEE-M", "WG-TEE-L"]
+    # Two images on the first two rows; third row has no image.
+    assert [r["Image Src"] for r in rows] == ["https://x/a.jpg", "https://x/b.jpg", ""]
+    assert [r["Image Position"] for r in rows] == ["1", "2", ""]
+
+
+def test_more_images_than_variants_emits_image_only_rows():
+    p = _product(images=[
+        CatalogImage(id=1, source_url="https://x/a.jpg", position=1, alt_text=None),
+        CatalogImage(id=2, source_url="https://x/b.jpg", position=2, alt_text=None),
+        CatalogImage(id=3, source_url="https://x/c.jpg", position=3, alt_text=None),
+    ])
+    rows = _rows([p])
+    assert len(rows) == 3  # 1 variant, 3 images
+    assert rows[0]["Variant SKU"] == "WG-MUG"
+    assert rows[1]["Variant SKU"] == "" and rows[1]["Handle"] == "moon-mug"
+    assert [r["Image Src"] for r in rows] == ["https://x/a.jpg", "https://x/b.jpg", "https://x/c.jpg"]
+
+
+import random
+
+from app.domains.products import codec, diff, validate
+
+
+def _gen_catalog(seed: int) -> dict:
+    """A deterministic random text-field catalog, in load_catalog()'s shape."""
+    rng = random.Random(seed)
+    words = ["moon", "star", "river", "cloud", "ember", "fern", "slate", "wave"]
+    catalog: dict[str, CatalogProduct] = {}
+    n_products = rng.randint(1, 6)
+    for pid in range(1, n_products + 1):
+        handle = "-".join(rng.sample(words, rng.randint(1, 3))) + f"-{pid}"
+        if handle in catalog:
+            continue
+        has_opts = rng.random() < 0.6
+        option_names = ("Size", "Color", None) if has_opts else (None, None, None)
+        tags = rng.sample(["apparel", "kitchen", "sale", "new"], rng.randint(0, 3))
+        fields = {
+            "title": f"{handle.title()} Thing",
+            "description_html": rng.choice([None, "<p>hi</p>"]),
+            "vendor": rng.choice([None, "Acme", "Wiggle Goods"]),
+            "product_type": "standalone",
+            "google_product_category": rng.choice([None, "Home & Garden"]),
+            "tags": tags,
+            "status": rng.choice(["draft", "active", "archived"]),
+            "published": rng.choice([True, False]),
+        }
+        variants = []
+        if has_opts:
+            sizes = rng.sample(["S", "M", "L", "XL"], rng.randint(1, 4))
+            for vi, size in enumerate(sizes, start=1):
+                # Non-sequential positions (×10) so a serializer that drops the
+                # stored position and lets re-import default to file order is
+                # caught — a merchant can import explicit positions like 10/20.
+                variants.append(CatalogVariant(
+                    id=pid * 100 + vi, options=(size, "Indigo", None), position=vi * 10,
+                    fields={"sku": f"SKU-{pid}-{vi}", "variant_image": None}))
+        else:
+            variants.append(CatalogVariant(
+                id=pid * 100 + 1, options=(None, None, None), position=rng.choice([1, 5, 9]),
+                fields={"sku": f"SKU-{pid}", "variant_image": None}))
+        images = []
+        for ii in range(rng.randint(0, 3)):
+            images.append(CatalogImage(
+                id=pid * 10 + ii, source_url=f"https://img/{handle}-{ii}.jpg",
+                position=ii + 1, alt_text=rng.choice([None, f"alt {ii}"])))
+        catalog[handle] = CatalogProduct(
+            id=pid, handle=handle, title=fields["title"], option_names=option_names,
+            fields=fields, variants=variants, images=images)
+    return catalog
+
+
+def _roundtrip_diff(catalog: dict) -> diff.DiffResult:
+    """export → bytes → import pipeline → diff against the same catalog."""
+    text = "".join(serialize.catalog_to_csv(catalog.values()))
+    parsed = codec.parse_csv(text.encode("utf-8"))
+    products = validate.build_products(parsed)
+    return diff.compute_diff(catalog, products)
+
+
+def test_inv12_roundtrip_is_noop_over_generated_catalogs():
+    for seed in range(200):
+        catalog = _gen_catalog(seed)
+        result = _roundtrip_diff(catalog)
+        assert result.summary["adds"] == 0, f"seed {seed}: {result.summary}"
+        assert result.summary["updates"] == 0, f"seed {seed}: {result.summary}"
+        assert result.summary["errors"] == 0, f"seed {seed}: {result.summary}"
+        assert result.summary["unchanged"] == len(catalog), f"seed {seed}"
+
+
+from decimal import Decimal
+
+
+def test_decimal_and_int_variant_fields_roundtrip():
+    catalog = {
+        "priced": CatalogProduct(
+            id=1, handle="priced", title="Priced",
+            option_names=(None, None, None),
+            fields={"title": "Priced", "description_html": None, "vendor": None,
+                    "product_type": "standalone", "google_product_category": None,
+                    "tags": [], "status": "active", "published": True},
+            variants=[CatalogVariant(
+                id=1, options=(None, None, None), position=1,
+                fields={"sku": "P1", "price": Decimal("18.00"),
+                        "cost": Decimal("9.5"), "weight": Decimal("0.250"),
+                        "inventory_qty": 40, "variant_image": None})],
+            images=[],
+        )
+    }
+    result = _roundtrip_diff(catalog)
+    assert result.summary["unchanged"] == 1, result.records
+    assert result.summary["updates"] == 0
+
+
+def test_nonsequential_variant_position_roundtrips():
+    """A stored variant position that isn't its file order must survive export —
+    else re-import reads the empty cell as 'reset to file order' and the round-trip
+    spuriously updates (INV-12 regression: position is a CatalogVariant attribute,
+    not a fields{} entry, so the serializer must emit it explicitly)."""
+    catalog = {
+        "tee": CatalogProduct(
+            id=1, handle="tee", title="Tee", option_names=("Size", None, None),
+            fields={"title": "Tee", "description_html": None, "vendor": None,
+                    "product_type": "standalone", "google_product_category": None,
+                    "tags": [], "status": "active", "published": True},
+            variants=[
+                CatalogVariant(id=1, options=("S", None, None), position=10,
+                               fields={"sku": "T-S", "variant_image": None}),
+                CatalogVariant(id=2, options=("M", None, None), position=20,
+                               fields={"sku": "T-M", "variant_image": None}),
+            ],
+            images=[],
+        )
+    }
+    result = _roundtrip_diff(catalog)
+    assert result.summary["unchanged"] == 1, result.records
+    assert result.summary["updates"] == 0

backend/tests/test_products_service.py

@@ -0,0 +1,222 @@
+"""products service — drafts: validate/preview/discard (PUC-2/3/3a/5a; INV-11)."""
+import json
+import logging
+
+import psycopg
+import pytest
+
+from app.domains import products
+from app.platform import db
+
+GOOD_CSV = b"Handle,Title,Vendor,Variant Price\nmoon-mug,Moon Mug,Acme,18.00\nstar-tee,Star Tee,Acme,24.00\n"
+
+
+@pytest.fixture()
+def migrated_conn(fresh_db_url):
+    with psycopg.connect(fresh_db_url) as conn:
+        db.migrate(conn)
+        yield conn
+
+
+@pytest.fixture()
+def merchant(migrated_conn):
+    acct = migrated_conn.execute(
+        "INSERT INTO account (email) VALUES ('m@example.com') RETURNING id").fetchone()[0]
+    sf = migrated_conn.execute(
+        "INSERT INTO storefront (name) VALUES ('Shop') RETURNING id").fetchone()[0]
+    migrated_conn.execute(
+        "INSERT INTO storefront_membership (account_id, storefront_id) VALUES (%s,%s)", (acct, sf))
+    migrated_conn.commit()
+    return {"account_id": acct, "storefront_id": sf}
+
+
+def test_import_validate_creates_draft_with_summary(migrated_conn, merchant):
+    draft = products.import_validate(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], "cat.csv", GOOD_CSV)
+    assert draft["dialect"] == "canonical"
+    assert draft["summary"] == {"adds": 2, "updates": 0, "unchanged": 0, "errors": 0}
+    assert draft["expires_at"]
+
+
+def test_validate_writes_nothing_to_catalog_inv11(migrated_conn, merchant):
+    products.import_validate(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], "cat.csv", GOOD_CSV)
+    assert migrated_conn.execute("SELECT count(*) FROM product").fetchone()[0] == 0
+    assert migrated_conn.execute("SELECT count(*) FROM variant").fetchone()[0] == 0
+
+
+def test_file_rejection_leaves_no_draft(migrated_conn, merchant):
+    with pytest.raises(products.FileRejected):
+        products.import_validate(
+            migrated_conn, merchant["storefront_id"], merchant["account_id"], "bad.csv",
+            b"Vendor,Price\nAcme,1\n")
+    assert migrated_conn.execute("SELECT count(*) FROM import_draft").fetchone()[0] == 0
+
+
+def test_records_paging_and_kind_filter(migrated_conn, merchant):
+    draft = products.import_validate(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], "cat.csv", GOOD_CSV)
+    recs = products.get_draft_records(migrated_conn, merchant["storefront_id"], draft["id"])
+    assert [r["handle"] for r in recs] == ["moon-mug", "star-tee"]
+    adds = products.get_draft_records(
+        migrated_conn, merchant["storefront_id"], draft["id"], kind="add", limit=1)
+    assert len(adds) == 1 and adds[0]["kind"] == "add"
+
+
+def test_discard_deletes_no_trace_puc3a(migrated_conn, merchant):
+    draft = products.import_validate(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], "cat.csv", GOOD_CSV)
+    products.discard_draft(migrated_conn, merchant["storefront_id"], draft["id"])
+    assert migrated_conn.execute("SELECT count(*) FROM import_draft").fetchone()[0] == 0
+    products.discard_draft(migrated_conn, merchant["storefront_id"], draft["id"])  # idempotent
+
+
+def test_draft_scoped_to_storefront_inv14(migrated_conn, merchant):
+    draft = products.import_validate(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], "cat.csv", GOOD_CSV)
+    other_sf = migrated_conn.execute(
+        "INSERT INTO storefront (name) VALUES ('Other') RETURNING id").fetchone()[0]
+    migrated_conn.commit()
+    with pytest.raises(products.DraftNotFound):
+        products.get_draft(migrated_conn, other_sf, draft["id"])
+
+
+def test_expired_draft_raises_and_lazily_deletes(migrated_conn, merchant):
+    draft = products.import_validate(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], "cat.csv", GOOD_CSV)
+    migrated_conn.execute(
+        "UPDATE import_draft SET expires_at = now() - interval '1 minute' WHERE id = %s",
+        (draft["id"],))
+    migrated_conn.commit()
+    with pytest.raises(products.DraftExpired):
+        products.get_draft(migrated_conn, merchant["storefront_id"], draft["id"])
+    assert migrated_conn.execute("SELECT count(*) FROM import_draft").fetchone()[0] == 0
+
+
+@pytest.fixture()
+def telemetry_propagation():
+    """create_app() sets propagate=False on the parent "ecomm" logger
+    (main._ensure_app_logging), which hides ecomm.telemetry records from caplog's
+    root-logger handler whenever an API test ran first. Restore propagation here."""
+    lg = logging.getLogger("ecomm")
+    prior = lg.propagate
+    lg.propagate = True
+    yield
+    lg.propagate = prior
+
+
+def test_tel1_emitted(migrated_conn, merchant, caplog, telemetry_propagation):
+    with caplog.at_level(logging.INFO, logger="ecomm.telemetry"):
+        products.import_validate(
+            migrated_conn, merchant["storefront_id"], merchant["account_id"], "cat.csv", GOOD_CSV)
+    events = [json.loads(r.message) for r in caplog.records if r.name == "ecomm.telemetry"]
+    assert any(
+        e["event"] == "import_draft_created" and e["adds"] == 2 and e["row_count"] == 2
+        and "duration_ms" in e and e["unknown_columns_count"] == 0
+        for e in events
+    )
+
+
+UPDATE_CSV = b"Handle,Title,Vendor,Variant Price\nmoon-mug,Moon Mug,Acme,21.00\nstar-tee,Star Tee,Acme,24.00\n"
+MIXED_CSV = b"Handle,Title,Variant Price\ngood-mug,Mug,10.00\nbad-tee,Tee,not-a-price\n"
+
+
+def _validate(conn, m, data=GOOD_CSV):
+    return products.import_validate(conn, m["storefront_id"], m["account_id"], "cat.csv", data)
+
+
+def test_confirm_applies_adds_and_records_run(migrated_conn, merchant):
+    draft = _validate(migrated_conn, merchant)
+    run_id = products.confirm_draft(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], draft["id"])
+    assert migrated_conn.execute("SELECT count(*) FROM product").fetchone()[0] == 2
+    run = products.get_run(migrated_conn, merchant["storefront_id"], run_id)
+    assert run["products_added"] == 2 and run["status"] == "complete"
+    assert run["by"] == "m@example.com"
+    assert run["image_progress"] == {"done": 0, "total": 0} and run["image_outcomes"] == []
+    assert migrated_conn.execute("SELECT count(*) FROM import_draft").fetchone()[0] == 0
+
+
+def test_confirm_update_changes_only_diffed_fields(migrated_conn, merchant):
+    d1 = _validate(migrated_conn, merchant)
+    products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d1["id"])
+    d2 = _validate(migrated_conn, merchant, UPDATE_CSV)
+    assert d2["summary"] == {"adds": 0, "updates": 1, "unchanged": 1, "errors": 0}
+    products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d2["id"])
+    price = migrated_conn.execute(
+        "SELECT v.price FROM variant v JOIN product p ON p.id = v.product_id WHERE p.handle='moon-mug'"
+    ).fetchone()[0]
+    assert str(price) == "21.00"
+    assert migrated_conn.execute("SELECT count(*) FROM product").fetchone()[0] == 2  # no dupes (BUC-3)
+
+
+def test_confirm_blank_position_cell_round_trips(migrated_conn, merchant):
+    # A present-but-empty Variant Position cell resolves to file order at diff
+    # time — never SET position = NULL (which would abort the confirm on the
+    # NOT NULL constraint).
+    d1 = _validate(migrated_conn, merchant)
+    products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d1["id"])
+    blank_position_csv = (
+        b"Handle,Title,Vendor,Variant Price,Variant Position\n"
+        b"moon-mug,Moon Mug,Acme,21.00,\n"
+        b"star-tee,Star Tee,Acme,24.00,\n"
+    )
+    d2 = _validate(migrated_conn, merchant, blank_position_csv)
+    products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d2["id"])
+    price = migrated_conn.execute(
+        "SELECT v.price FROM variant v JOIN product p ON p.id = v.product_id WHERE p.handle='moon-mug'"
+    ).fetchone()[0]
+    assert str(price) == "21.00"
+
+
+def test_confirm_mixed_applies_valid_records_errors(migrated_conn, merchant):
+    draft = _validate(migrated_conn, merchant, MIXED_CSV)
+    run_id = products.confirm_draft(
+        migrated_conn, merchant["storefront_id"], merchant["account_id"], draft["id"])
+    assert migrated_conn.execute("SELECT count(*) FROM product").fetchone()[0] == 1
+    run = products.get_run(migrated_conn, merchant["storefront_id"], run_id)
+    assert run["rows_errored"] == 1
+    assert run["errors"][0]["column"] == "Variant Price"
+
+
+def test_confirm_stale_fingerprint_409_inv11(migrated_conn, merchant):
+    draft = _validate(migrated_conn, merchant)
+    other = _validate(migrated_conn, merchant)
+    products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], other["id"])
+    with pytest.raises(products.PreviewStale):
+        products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], draft["id"])
+
+
+def test_confirm_nothing_to_apply_puc10(migrated_conn, merchant):
+    d1 = _validate(migrated_conn, merchant)
+    products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d1["id"])
+    d2 = _validate(migrated_conn, merchant)
+    assert d2["summary"]["unchanged"] == 2
+    with pytest.raises(products.NothingToApply):
+        products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d2["id"])
+
+
+def test_runs_history_newest_first(migrated_conn, merchant):
+    d1 = _validate(migrated_conn, merchant)
+    products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d1["id"])
+    d2 = _validate(migrated_conn, merchant, UPDATE_CSV)
+    r2 = products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d2["id"])
+    runs = products.list_runs(migrated_conn, merchant["storefront_id"])
+    assert [r["id"] for r in runs][0] == r2
+
+
+def test_summary_counts(migrated_conn, merchant):
+    assert products.summary(migrated_conn, merchant["storefront_id"]) == {
+        "product_count": 0, "image_problem_count": 0, "latest_run_id": None}
+    d = _validate(migrated_conn, merchant)
+    rid = products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], d["id"])
+    s = products.summary(migrated_conn, merchant["storefront_id"])
+    assert s == {"product_count": 2, "image_problem_count": 0, "latest_run_id": rid}
+
+
+def test_tel2_emitted_on_confirm(migrated_conn, merchant, caplog, telemetry_propagation):
+    draft = _validate(migrated_conn, merchant)
+    with caplog.at_level(logging.INFO, logger="ecomm.telemetry"):
+        products.confirm_draft(migrated_conn, merchant["storefront_id"], merchant["account_id"], draft["id"])
+    events = [json.loads(r.message) for r in caplog.records if r.name == "ecomm.telemetry"]
+    assert any(e["event"] == "import_run_completed" and e["added"] == 2 for e in events)

backend/tests/test_products_validate.py

@@ -0,0 +1,164 @@
+"""§6.5.1 row validation — every row-error rule has a fixture (SD-0002 §6.8)."""
+from decimal import Decimal
+
+import pytest
+
+from app.domains.products.codec import parse_csv
+from app.domains.products.validate import build_products
+
+
+def _products(*lines: str):
+    return build_products(parse_csv(("\n".join(lines) + "\n").encode()))
+
+
+def _errors(*lines: str):
+    return [e for p in _products(*lines) for e in p.errors]
+
+
+def test_simple_product_parses_clean():
+    [p] = _products(
+        "Handle,Title,Vendor,Tags,Status,Published,Variant Price,Variant SKU",
+        "moon-mug,Moon Mug,Acme,\"kitchen, mugs\",active,TRUE,18.00,SKU-1",
+    )
+    assert p.valid and p.handle == "moon-mug" and p.title == "Moon Mug"
+    assert p.fields["tags"] == ["kitchen", "mugs"]
+    assert p.fields["status"] == "active" and p.fields["published"] is True
+    [v] = p.variants
+    assert v.options == (None, None, None)
+    assert v.fields["price"] == Decimal("18.00") and v.fields["sku"] == "SKU-1"
+
+
+def test_option_product_groups_consecutive_rows():
+    [p] = _products(
+        "Handle,Title,Option1 Name,Option1 Value,Variant Price",
+        "tee,Tee,Size,S,24.00",
+        "tee,,,M,24.00",
+        "tee,,,L,26.00",
+    )
+    assert p.valid and p.option_names == ("Size", None, None)
+    assert [v.options[0] for v in p.variants] == ["S", "M", "L"]
+
+
+def test_image_only_rows_and_dedupe():
+    [p] = _products(
+        "Handle,Title,Image Src,Image Position,Image Alt Text",
+        "mug,Mug,https://x/a.jpg,1,front",
+        "mug,,https://x/b.jpg,2,back",
+        "mug,,https://x/a.jpg,3,dupe",
+    )
+    assert p.valid
+    assert [(i.source_url, i.position) for i in p.images] == [
+        ("https://x/a.jpg", 1), ("https://x/b.jpg", 2),
+    ]
+
+
+def test_variant_image_joins_product_images():
+    [p] = _products(
+        "Handle,Title,Variant Image",
+        "mug,Mug,https://x/v.jpg",
+    )
+    assert p.variants[0].fields["variant_image"] == "https://x/v.jpg"
+    assert [i.source_url for i in p.images] == ["https://x/v.jpg"]
+
+
+def test_description_sanitized_inv15():
+    [p] = _products(
+        "Handle,Title,Description",
+        'mug,Mug,"<p onclick=\'x()\'>hi</p><script>evil()</script>"',
+    )
+    html = p.fields["description_html"]
+    assert "<p>" in html and "script" not in html and "onclick" not in html
+
+
+def test_blank_cell_clears_absent_column_missing():
+    [p] = _products("Handle,Title,Vendor", "mug,Mug,")
+    assert p.fields["vendor"] is None          # present-but-empty == clear
+    assert "status" not in p.fields            # absent column == untouched
+
+
+@pytest.mark.parametrize(
+    "header,row,column,fragment",
+    [
+        ("Handle,Title", ",NoHandle", "Handle", "needs a Handle"),
+        ("Handle,Title", "Bad_Handle!,T", "Handle", "isn't a valid handle"),
+        ("Handle,Title", "mug,", "Title", "missing its Title"),
+        ("Handle,Title,Type", "mug,Mug,kit_virtual", "Type", "kits arrive"),
+        ("Handle,Title,Component 1 SKU", "mug,Mug,ABC", "Component 1 SKU", "kits arrive"),
+        ("Handle,Title,Status", "mug,Mug,live", "Status", "is not a status"),
+        ("Handle,Title,Published", "mug,Mug,YES", "Published", "is not TRUE or FALSE"),
+        ("Handle,Title,Variant Price", 'mug,Mug,"12,50"', "Variant Price", "is not a price"),
+        ("Handle,Title,Variant Cost", "mug,Mug,-3", "Variant Cost", "is not a price"),
+        ("Handle,Title,Variant Weight", "mug,Mug,heavy", "Variant Weight", "is not a number"),
+        ("Handle,Title,Variant Inventory Qty", "mug,Mug,3.5", "Variant Inventory Qty", "is not a whole number"),
+        ("Handle,Title,Variant Position", "mug,Mug,0", "Variant Position", "is not a position"),
+        ("Handle,Title,Option1 Value", "mug,Mug,Red", "Option1 Value", "no Option1 Name"),
+    ],
+)
+def test_row_error_rules(header, row, column, fragment):
+    errors = _errors(header, row)
+    assert any(e.column == column and fragment in e.message for e in errors), errors
+
+
+def test_missing_option_value_for_named_option():
+    errors = _errors(
+        "Handle,Title,Option1 Name,Option1 Value,Variant SKU",
+        "tee,Tee,Size,S,A",
+        "tee,,,,B",
+    )
+    assert any("missing its Option1 Value" in e.message and e.line_number == 3 for e in errors)
+
+
+def test_duplicate_option_combo_is_error():
+    errors = _errors(
+        "Handle,Title,Option1 Name,Option1 Value",
+        "tee,Tee,Size,S",
+        "tee,,,S",
+    )
+    assert any("duplicate variant" in e.message for e in errors)
+
+
+def test_second_variant_on_no_option_product_is_error():
+    errors = _errors(
+        "Handle,Title,Variant SKU",
+        "mug,Mug,A",
+        "mug,,B",
+    )
+    assert any("without options can have only one variant" in e.message for e in errors)
+
+
+def test_non_consecutive_handle_is_error():
+    errors = _errors(
+        "Handle,Title",
+        "mug,Mug",
+        "tee,Tee",
+        "mug,",
+    )
+    assert any("must be consecutive" in e.message and e.line_number == 4 for e in errors)
+
+
+def test_no_data_row_is_error():
+    errors = _errors(
+        "Handle,Title,Variant SKU,Image Src",
+        "mug,Mug,A,",
+        "mug,,,",
+    )
+    assert any("no variant or image data" in e.message for e in errors)
+
+
+def test_errors_poison_their_product_only():
+    products = _products(
+        "Handle,Title,Variant Price",
+        "good-mug,Mug,10.00",
+        "bad-tee,Tee,not-a-price",
+    )
+    by_handle = {p.handle: p for p in products}
+    assert by_handle["good-mug"].valid
+    assert not by_handle["bad-tee"].valid
+
+
+def test_all_errors_collected_not_first_only():
+    [p] = _products(
+        "Handle,Title,Status,Variant Price",
+        "mug,,bogus,abc",
+    )
+    assert len(p.errors) == 3  # missing Title + bad status + bad price

docs/OPERATIONS.md

@@ -0,0 +1,125 @@
+# Operating ecomm
+
+The framework-repo operator guide (SD-0002 DOC-1), started at SLICE-5. It covers
+the app's operational surface — telemetry, runbooks, alert gestures, the E2E
+gate. Per-deployment mechanics (deploy, secrets, VM access) live in the
+deployment's flotilla docs and `deployment.toml`; environment bring-up is in
+[`BOOTSTRAP.md`](./BOOTSTRAP.md).
+
+## Products import/export ops (SD-0002, SLICE-5)
+
+The §6.4 surface: a merchant uploads a catalog CSV (`POST
+/api/products/imports`), the app validates it and stores an **import draft**
+with a full preview (adds / updates / unchanged / errors), the merchant
+confirms or cancels at the preview gate, and a confirm applies the previewed
+diff as one **import run** recorded in the history (`/api/products/imports/runs`).
+
+Caps and behavior to know (all enforced in code, not config):
+
+- **Caps (INV-18):** ≤ 5,000 data rows and ≤ 10 MB per file —
+  `MAX_DATA_ROWS` / `MAX_FILE_BYTES` in `backend/app/domains/products/models.py`,
+  enforced in `backend/app/domains/products/codec.py` (file-level rejection)
+  plus a 413 `file_too_large` guard in the BFF (`backend/app/main.py`).
+- **Draft expiry:** ~1 hour (`expires_at = now() + interval '1 hour'`). Cleanup
+  is a lazy sweep — expired drafts are deleted on the next upload and on any
+  access to an expired draft; there is no background job to babysit.
+- **Upsert-only (INV-10):** an import adds and updates, never deletes. Catalog
+  products/variants/images absent from the file are untouched.
+- **One-transaction apply (INV-11):** a confirm applies the whole previewed
+  diff in a single DB transaction — it lands completely or not at all.
+
+### Telemetry
+
+Structured JSON events on the `ecomm.telemetry` logger
+(`backend/app/platform/telemetry.py`), one JSON object per line, emitted from
+`backend/app/domains/products/service.py`. The app's `ecomm.*` log handler
+writes to the process's stderr, which journald captures on the VM (and Cloud
+Logging where the agent ships it). Events carry counts and durations only —
+never file names, URLs, catalog content, or secret bytes.
+
+| Event | Trigger | Payload fields |
+| --- | --- | --- |
+| TEL-1 `import_draft_created` | validation completes, draft stored | `storefront_id, dialect, row_count, adds, updates, unchanged, errors, unknown_columns_count, duration_ms` |
+| TEL-2 `import_run_completed` | apply transaction commits | `run_id, storefront_id, added, updated, errored, duration_ms` |
+| TEL-3 `catalog_exported` | export stream completes | `storefront_id, status_filter, product_count, duration_ms` |
+| TEL-6 `import_apply_failed` | apply transaction aborts unexpectedly | `draft_id, storefront_id, error_class` |
+
+### Export (PUC-9, SLICE-6)
+
+`GET /api/products/export?status=all|active|draft|archived` streams the
+storefront's catalog as a canonical-format CSV (one codec, two directions — the
+same format the importer parses). It is **read-only** (no draft, no run) and
+storefront-scoped (INV-14). An empty catalog — no products, or none matching the
+status filter — returns `409 empty_catalog`; the Products page disables the
+Export action with a note in that case. The round-trip is lossless (INV-12):
+re-importing an unmodified export previews as all-unchanged with the import
+action disabled (PUC-10). TEL-3 (`catalog_exported`) is emitted once the stream
+completes — counts and duration only, never catalog content.
+
+### RB-2 — import apply failed
+
+Triggered by ALR-2 (any TEL-6 event). The apply raised mid-transaction and
+rolled back.
+
+1. **Locate the failure.** On the VM, filter the journal for the event and note
+   the `draft_id`, `storefront_id`, and `error_class`:
+
+   ```
+   journalctl -u ecomm.service | grep import_apply_failed
+   ```
+
+2. **Confirm the rollback held (INV-11).** The apply is one transaction, so a
+   failure leaves the catalog exactly as it was: the storefront's runs history
+   (`GET /api/products/imports/runs`) shows **no new run**, and the products
+   summary (`GET /api/products/summary`) shows an unchanged `product_count`.
+3. **The merchant's draft is intact.** A failed apply does not consume the
+   draft — the merchant can retry confirm, or re-upload if the draft has since
+   expired (~1 h). Advise accordingly.
+4. **File a bug** on `wiggleverse/wiggleverse-ecomm` with the `error_class`
+   and the surrounding log context (the traceback is in the app log next to
+   the event).
+
+### ALR-2 — the log-based alert (one gesture per environment)
+
+Run once per environment, at this slice's PPE deploy. This is an ad hoc op on
+the existing GCP project (`wiggleverse-ecomm`), not a provisioning gesture.
+
+```
+# Select the deployment's gcloud config for this one process (handbook §8.4).
+export CLOUDSDK_ACTIVE_CONFIG_NAME=wiggleverse-ecomm
+
+# Log-based metric counting import-apply failures (TEL-6).
+gcloud logging metrics create ecomm_import_apply_failed \
+  --description="ecomm TEL-6 import_apply_failed events (SD-0002 ALR-2)" \
+  --log-filter='resource.type="gce_instance" AND jsonPayload.message:"import_apply_failed" OR textPayload:"import_apply_failed"'
+```
+
+Then attach an alert policy to the metric — **operator email channel, threshold
+any event > 0 in 5 minutes, severity notify-only** (pre-v1: no paging). The
+policy is created in the Cloud Console or with
+`gcloud alpha monitoring policies create`; the exact command depends on the
+notification-channel id, so list channels first:
+
+```
+# Find the operator email channel's id for the policy.
+gcloud beta monitoring channels list
+```
+
+### E2E browser suite
+
+- Lives at `e2e/` — Playwright, Chromium, six scenarios (SLICE-5:
+  preview/confirm happy path, actionable errors, file rejection, cancel;
+  SLICE-6: `e2e_export_download`, `e2e_roundtrip_noop`).
+- Run with `bash scripts/e2e.sh`. The harness boots a **fresh `ecomm_e2e`
+  database** against the local compose Postgres and serves the built SPA from
+  the backend on **:8765** (the deployed topology), so it needs the dev
+  Postgres up (`scripts/dev.sh`).
+- **Not in `scripts/check.sh` / CI yet** — the Gitea runner has no browsers
+  (the §10.6 machinery gap). Run it locally before merge, and against PPE per
+  the §9 pipeline (the PPE browser run is still manual this slice).
+
+## Cross-references
+
+- SLO and alert definitions: SD-0002 §9–§10 (content repo,
+  `wiggleverse-ecomm-content/specs/SD-0002-products-bulk-csv-import-export.md`).
+- Import/diff engine internals: [`products-domain.md`](./products-domain.md).

docs/products-domain.md

@@ -0,0 +1,147 @@
+# products domain — developer notes
+
+DOC-4 (SD-0002 §11): the import/export spine as built in SLICE-5, extended by
+SLICE-6–8. Operator-facing material is in [`OPERATIONS.md`](./OPERATIONS.md);
+the spec is SD-0002 in the content repo.
+
+## Layout and pipeline
+
+`backend/app/domains/products/` is layered like the rest of the app
+(main → domains → platform, enforced by import-linter):
+
+- `models.py` — canonical row model + the column registry.
+- `codec.py` — bytes → `ParsedFile`; file-level gates only.
+- `validate.py` — rows → `CanonicalProduct` blocks + per-row errors.
+- `diff.py` — catalog × canonical products → apply plan + preview records.
+- `serialize.py` — the export half: `CatalogProduct` snapshot → canonical CSV
+  (the inverse of `codec`/`validate`). DB-free, like `diff.py`.
+- `repo.py` — SQL only: catalog snapshot, draft/run CRUD, apply primitives.
+  Never commits or rolls back.
+- `service.py` — use-case orchestration; owns every transaction boundary and
+  emits the TEL events via `backend/app/platform/telemetry.py`.
+
+```mermaid
+flowchart LR
+    subgraph validate_path [import_validate]
+        A[parse_csv] --> B[build_products] --> D[compute_diff] --> E[(import_draft)]
+        C[load_catalog] --> D
+    end
+    subgraph confirm_path [confirm_draft]
+        E --> F[re-derive: parse → build → diff] --> G{fingerprint match?}
+        G -- yes --> H[one-transaction apply<br/>run + products + delete draft]
+        G -- no --> I[PreviewStale<br/>draft kept]
+    end
+```
+
+Confirm re-derives everything from the draft's stored `file_bytes` against the
+live catalog, then checks the fingerprint — so what lands is exactly what the
+preview showed, or the confirm refuses (`preview_stale`). A confirm with no
+adds and no updates refuses with `nothing_to_apply`.
+
+## Canonical model and blank-vs-absent
+
+`models.py` is the one model every dialect maps to (INV-17). `KNOWN_COLUMNS`
+is the registry header detection, unknown-column warnings, and validation all
+read; `CLEAR_DEFAULTS` holds the reset values for clearable fields
+(`status`, `published`, `product_type`, `tags`).
+
+The §6.5.1 cell semantics, as implemented:
+
+- **Absent column** → the field never enters `fields{}` → untouched by diff
+  and apply (never a change).
+- **Present-but-empty cell** → `fields[name] = None` (an explicit clear) →
+  resolved at diff time to its `CLEAR_DEFAULTS` entry, or NULL where none
+  exists.
+- **The position exception:** a cleared `Variant Position` has no
+  `CLEAR_DEFAULTS` entry — `diff.resolved_variant_fields` resolves it to the
+  variant's 1-based file order within its product, never to NULL.
+
+Option names live both in `CanonicalProduct.option_names` (the values) and in
+`fields{}` (the file-presence marker the diff needs for the absent-vs-clear
+distinction).
+
+## Error granularity
+
+`validate.py` never raises on a row problem: every violation is recorded as a
+merchant-language `RowError` and **poisons its whole product block** — the
+product previews as `kind="error"` and is excluded from apply, while parsing
+continues so one pass yields a complete accounting (BUC-1a). On apply, error
+rows are recorded per line in `import_run_error`; `rows_errored` on the run is
+the **error-row count**, while the preview's errors tile counts error
+**products** — the two numbers legitimately differ.
+
+File-level problems (`not_csv`, `missing_required_column`, `too_many_rows`,
+`file_too_large`) raise `FileRejected` in `codec.py` instead: no draft is
+created. The BFF adds an early 413 for oversized uploads (`main.py`).
+
+## INV-11 mechanics
+
+`compute_diff` makes **one walk** that produces two views of the same
+computation: the typed apply `plan` (resolved natives — `Decimal`, `bool`,
+lists) that `confirm_draft` executes, and the JSON-safe preview `records`
+stored as draft JSONB and served verbatim to the SPA. Because both derive from
+the same walk they cannot diverge. The `fingerprint` is
+`sha256(json.dumps(records, sort_keys=True, separators=(",", ":")))`; a
+mismatch at confirm means the catalog drifted since preview → `PreviewStale`
+(409 `preview_stale`, draft kept for re-validation). The whole apply — run row,
+product/variant/image writes, error rows, draft delete — is one transaction;
+any exception rolls it back and emits TEL-6.
+
+## Export & the round-trip (SLICE-6)
+
+`serialize.py` is the export half of "one codec, two directions": it turns the
+`CatalogProduct` snapshot (the same one `repo.load_catalog` builds for the diff
+engine) back into canonical CSV, writing exactly the columns `codec.py` /
+`validate.py` parse, in the §6.5.1 row grammar — `HEADER` is the full canonical
+column set; product fields + option names sit on the first row; one variant per
+row; images interleave; a product with more images than variants emits
+image-only rows.
+
+`repo.export_catalog` returns the status-filtered snapshot list (sorted by
+handle, deterministic); the `service.export_catalog` generator streams
+`serialize.catalog_to_csv` over it and emits TEL-3 (`catalog_exported`) once the
+stream is exhausted. The BFF wraps it in a `StreamingResponse`; an empty
+(filtered) catalog raises `EmptyCatalog` **eagerly** → `409 empty_catalog`
+before any bytes stream.
+
+**INV-12** (`diff(catalog, import(export(catalog))) = ∅`) is locked two ways: a
+property test (`test_products_serialize.py`) runs the real
+export→parse→diff loop over 200 generated **text-field** catalogs and asserts
+every product is `unchanged`; the `e2e_roundtrip_noop` browser scenario does the
+same through the UI (export download → re-upload → all-unchanged preview, import
+disabled). Numeric/`Decimal` fields — the property test's deliberate blind spot
+(string-form vs value-identity) — get explicit round-trip unit tests.
+
+## Named seams (what later slices replace)
+
+- **`import_draft.file_bytes` → objectstore key (SLICE-7).** The upload
+  currently lives as BYTEA on the draft row (`0002_products.sql`); SLICE-7
+  moves the bytes to object storage and stores a key.
+- **`codec.detect_dialect` → Shopify (SLICE-8).** Today it always returns
+  `"canonical"`; SLICE-8 recognizes Shopify's exact header set here (INV-17).
+- **Run-status complete shortcut → `fetching_images` (SLICE-7).**
+  `confirm_draft` inserts the run with `status="complete"` directly; SLICE-7
+  inserts it as `fetching_images` and hands off to the image-fetch task.
+  Relatedly, image rows are created with the schema default
+  `status='pending'` **today and stay pending** — placeholder behavior until
+  SLICE-7's fetch phase (the run-detail payload already carries the stable
+  `image_progress` / `image_outcomes` shape, zeroed).
+
+## Test map
+
+| File | Covers |
+| --- | --- |
+| `backend/tests/test_products_codec.py` | file-level gates: parse, caps (INV-18), required columns, dialect |
+| `backend/tests/test_products_validate.py` | every §6.5.1 row-error rule, one fixture each |
+| `backend/tests/test_products_diff.py` | classification, blank-vs-absent, option matching, fingerprint |
+| `backend/tests/test_products_serialize.py` | serializer grammar + INV-12 property test (round-trip no-op over generated catalogs) + decimal round-trip |
+| `backend/tests/test_products_export.py` | status-filtered snapshot, streamed export, EmptyCatalog, TEL-3 |
+| `backend/tests/test_products_service.py` | draft lifecycle: validate/preview/discard, expiry, TEL-1 |
+| `backend/tests/test_products_invariants.py` | INV-10 (never deletes), INV-14 (storefront isolation), apply transactionality, TEL-6 |
+| `backend/tests/test_products_endpoints.py` | §6.4 API scenarios + auth/storefront gates |
+| `e2e/tests/import-preview-confirm.spec.ts` | happy path: upload → preview → confirm → history |
+| `e2e/tests/import-errors.spec.ts` | actionable row errors at preview and on the run report |
+| `e2e/tests/import-file-rejected.spec.ts` | file-level rejection, picker stays live, no trace |
+| `e2e/tests/import-cancel.spec.ts` | cancel at preview leaves no trace |
+| `e2e/tests/export-download.spec.ts` | export downloads canonical CSV, status filter respected |
+| `e2e/tests/roundtrip-noop.spec.ts` | export → re-import → all-unchanged, import disabled (PUC-10) |

e2e/.gitignore

@@ -0,0 +1,4 @@
+node_modules/
+.backend.log
+test-results/
+playwright-report/

e2e/fixtures/good.csv

@@ -0,0 +1,4 @@
+Handle,Title,Vendor,Tags,Status,Published,Option1 Name,Option1 Value,Variant SKU,Variant Price,Variant Inventory Qty
+moon-mug,Moon Mug,Wiggle Goods,"kitchen, mugs",active,TRUE,,,WG-MUG-001,18.00,40
+star-tee,Star Tee,Wiggle Goods,apparel,active,TRUE,Size,S,WG-TEE-S,24.00,12
+star-tee,,,,,,,M,WG-TEE-M,24.00,18

e2e/fixtures/missing-title.csv

@@ -0,0 +1,2 @@
+Handle,Vendor
+mug,Acme

e2e/fixtures/mixed-errors.csv

@@ -0,0 +1,4 @@
+Handle,Title,Variant Price
+good-mug,Good Mug,10.00
+bad-tee,Bad Tee,not-a-price
+also-good,Also Good,5.00

e2e/helpers.ts

@@ -0,0 +1,110 @@
+// Shared E2E helpers — the sign-up journey (SD-0001 §5.1–§5.4) and products-page
+// navigation (SD-0002 §5.2). Selectors are role/label-based against the real screens
+// (Landing.tsx, SignIn.tsx, CreateStorefront.tsx, Admin.tsx, ProductsPage.tsx).
+import { expect, type Page } from "@playwright/test";
+import { readFile, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+const LOG = join(__dirname, ".backend.log");
+let seq = 0;
+
+// The storefront name every helper-created merchant uses; tests assert against it.
+export const STOREFRONT_NAME = "E2E Test Goods";
+
+export function freshEmail(): string {
+  return `merchant${Date.now()}-${seq++}@example.com`;
+}
+
+// LogMailer's exact line (backend/app/platform/mailer.py):
+//   INFO:ecomm.mailer: LogMailer -> <to> | Your ecomm code: <6 digits>\n<body>
+// The first 6-digit group after the marker is the code.
+async function codeFor(email: string): Promise<string> {
+  for (let i = 0; i < 50; i++) {
+    const log = await readFile(LOG, "utf8").catch(() => "");
+    const at = log.lastIndexOf(`LogMailer -> ${email}`);
+    if (at >= 0) {
+      const m = log.slice(at).match(/\b(\d{6})\b/);
+      if (m) return m[1];
+    }
+    await new Promise((r) => setTimeout(r, 200));
+  }
+  throw new Error(`no code logged for ${email}`);
+}
+
+export async function signUpWithStorefront(page: Page, email = freshEmail()): Promise<string> {
+  // Landing → the sign-up door.
+  await page.goto("/");
+  await page.getByRole("button", { name: "Create your storefront →" }).click();
+
+  // Sign-in step 1: request the one-time code.
+  await page.getByLabel("Email").fill(email);
+  await page.getByRole("button", { name: "Send code" }).click();
+
+  // Sign-in step 2: read the code from the backend log and verify it.
+  await expect(page.getByRole("heading", { name: "Check your email" })).toBeVisible();
+  const code = await codeFor(email);
+  await page.getByLabel("One-time code").fill(code);
+  await page.getByRole("button", { name: "Continue" }).click();
+
+  // Create-storefront screen (a new account has none yet).
+  await expect(page.getByRole("heading", { name: "Create your storefront" })).toBeVisible();
+  await page.getByLabel("Storefront name").fill(STOREFRONT_NAME);
+  await page.getByRole("button", { name: "Create storefront", exact: true }).click();
+
+  // Admin shell: nav strip + the storefront identity in the topbar.
+  await expect(page.getByRole("navigation", { name: "Admin sections" })).toBeVisible();
+  await expect(page.locator(".storeid__name")).toHaveText(STOREFRONT_NAME);
+  return email;
+}
+
+export async function gotoProducts(page: Page) {
+  await page
+    .getByRole("navigation", { name: "Admin sections" })
+    .getByRole("link", { name: "Products" })
+    .click();
+  await expect(page.getByRole("heading", { level: 1, name: "Products" })).toBeVisible();
+}
+
+export async function uploadFixture(page: Page, fixture: string) {
+  // Two "Import products" links render on the empty products page (header + empty
+  // state) — same destination, so take the first.
+  await page.getByRole("link", { name: "Import products" }).first().click();
+  await expect(page.getByRole("heading", { name: "Import products" })).toBeVisible();
+  await page.locator('input[type="file"]').setInputFiles(join(__dirname, "fixtures", fixture));
+}
+
+// Import good.csv and confirm it, leaving a 2-product catalog. Returns nothing;
+// callers continue from the run-detail screen.
+export async function importGoodCsv(page: Page) {
+  await uploadFixture(page, "good.csv");
+  await expect(page.getByRole("heading", { name: "Import preview — good.csv" })).toBeVisible();
+  await page.getByRole("button", { name: "Import 2 products" }).click();
+  await expect(page.getByRole("heading", { level: 1, name: "good.csv" })).toBeVisible();
+}
+
+// Click an Export status option and capture the downloaded CSV's text + path.
+export async function exportCatalog(page: Page, label: string): Promise<{ text: string; path: string }> {
+  // Open the <details> menu, then click the status option, capturing the download.
+  // The menu is a native <details> that *toggles* on each summary click and is
+  // NOT closed by clicking a download <a> (a download doesn't navigate). So on a
+  // second export the menu may already be open — deterministically open it
+  // rather than blind-toggling, and wait for the status link to be visible.
+  const details = page.locator("details.products__export");
+  if (!(await details.evaluate((el: HTMLDetailsElement) => el.open))) {
+    await details.locator("> summary").click();
+  }
+  const link = page.getByRole("link", { name: label, exact: true });
+  await expect(link).toBeVisible();
+  const [download] = await Promise.all([
+    page.waitForEvent("download"),
+    link.click(),
+  ]);
+  const stream = await download.createReadStream();
+  const chunks: Buffer[] = [];
+  for await (const c of stream) chunks.push(c as Buffer);
+  const text = Buffer.concat(chunks).toString("utf8");
+  const path = join(tmpdir(), `export-${Date.now()}.csv`);
+  await writeFile(path, text, "utf8");
+  return { text, path };
+}

e2e/package-lock.json

@@ -0,0 +1,76 @@
+{
+  "name": "wiggleverse-ecomm-e2e",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "wiggleverse-ecomm-e2e",
+      "devDependencies": {
+        "@playwright/test": "^1.48.0"
+      }
+    },
+    "node_modules/@playwright/test": {
+      "version": "1.60.0",
+      "resolved": "https://registry.npmjs.org/@playwright/test/-/test-1.60.0.tgz",
+      "integrity": "sha512-O71yZIbAh/PxDMNGns37GHBIfrVkEVyn+AXyIa5dOTfb4/xNvRWV+Vv/NMbNCtODB/pO7vLlF2OTmMVLhmr7Ag==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright": "1.60.0"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
+    "node_modules/fsevents": {
+      "version": "2.3.2",
+      "resolved": "https://registry.npmjs.org/fsevents/-/fsevents-2.3.2.tgz",
+      "integrity": "sha512-xiqMQR4xAeHTuB9uWm+fFRcIOgKBMiOBP+eXiyT7jsgVCq1bkVygt00oASowB7EdtpOHaaPgKt812P9ab+DDKA==",
+      "dev": true,
+      "hasInstallScript": true,
+      "license": "MIT",
+      "optional": true,
+      "os": [
+        "darwin"
+      ],
+      "engines": {
+        "node": "^8.16.0 || ^10.6.0 || >=11.0.0"
+      }
+    },
+    "node_modules/playwright": {
+      "version": "1.60.0",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.60.0.tgz",
+      "integrity": "sha512-hheHdokM8cdqCb0lcE3s+zT4t4W+vvjpGxsZlDnikarzx8tSzMebh3UiFtgqwFwnTnjYQcsyMF8ei2mCO/tpeA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright-core": "1.60.0"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "optionalDependencies": {
+        "fsevents": "2.3.2"
+      }
+    },
+    "node_modules/playwright-core": {
+      "version": "1.60.0",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.60.0.tgz",
+      "integrity": "sha512-9bW6zvX/m0lEbgTKJ6YppOKx8H3VOPBMOCFh2irXFOT4BbHgrx5hPjwJYLT40Lu+4qtD36qKc/Hn56StUW57IA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "playwright-core": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    }
+  }
+}

e2e/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "wiggleverse-ecomm-e2e",
+  "private": true,
+  "scripts": { "test": "playwright test" },
+  "devDependencies": { "@playwright/test": "^1.48.0" }
+}

e2e/playwright.config.ts

@@ -0,0 +1,16 @@
+import { defineConfig } from "@playwright/test";
+
+export default defineConfig({
+  testDir: "./tests",
+  timeout: 60_000,
+  retries: 0,
+  // One shared backend + log file; parallel sign-ins would interleave codes.
+  workers: 1,
+  use: { baseURL: "http://localhost:8765" },
+  webServer: {
+    command: "bash ./serve.sh",
+    url: "http://localhost:8765/healthz",
+    reuseExistingServer: false,
+    timeout: 120_000,
+  },
+});

e2e/serve.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# E2E server: fresh ecomm_e2e database, LogMailer (codes land in .backend.log),
+# backend on :8765 serving the built SPA (the deployed topology, SD-0001 §6.2).
+set -euo pipefail
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+if [ ! -f "$repo_root/frontend/dist/index.html" ]; then
+  ( cd "$repo_root/frontend" && npm run build )
+fi
+
+"$repo_root/.venv/bin/python" - <<'PY'
+import psycopg
+admin = psycopg.connect("postgresql://ecomm:ecomm@localhost:5432/postgres", autocommit=True)
+admin.execute("SELECT pg_terminate_backend(pid) FROM pg_stat_activity WHERE datname='ecomm_e2e' AND pid <> pg_backend_pid()")
+admin.execute("DROP DATABASE IF EXISTS ecomm_e2e")
+admin.execute("CREATE DATABASE ecomm_e2e")
+PY
+
+export ECOMM_DATABASE_URL="postgresql://ecomm:ecomm@localhost:5432/ecomm_e2e"
+export ECOMM_MAILER=log
+cd "$repo_root/backend"
+exec "$repo_root/.venv/bin/python" -m uvicorn app.main:app --port 8765 \
+  > "$repo_root/e2e/.backend.log" 2>&1

e2e/tests/export-download.spec.ts

@@ -0,0 +1,21 @@
+// DoD scenario e2e_export_download (SD-0002 §6.8): export downloads a canonical
+// CSV and the status filter is respected.
+import { expect, test } from "@playwright/test";
+import { exportCatalog, gotoProducts, importGoodCsv, signUpWithStorefront } from "../helpers";
+
+test("e2e_export_download", async ({ page }) => {
+  await signUpWithStorefront(page);
+  await gotoProducts(page);
+  await importGoodCsv(page);
+  await gotoProducts(page);
+
+  // Export "All products" → a canonical CSV with both handles.
+  const all = await exportCatalog(page, "All products");
+  expect(all.text.split("\n")[0]).toContain("Handle,");
+  expect(all.text).toContain("moon-mug");
+  expect(all.text).toContain("star-tee");
+
+  // good.csv's products are active → "Active" exports both, "Draft" is empty/disabled-path.
+  const active = await exportCatalog(page, "Active");
+  expect(active.text).toContain("moon-mug");
+});

e2e/tests/import-cancel.spec.ts

@@ -0,0 +1,23 @@
+// DoD scenario e2e_import_cancel_no_trace (SD-0002 §6.8): cancelling at the
+// preview gate (PUC-3a) leaves no trace — no products, no run in the history.
+import { expect, test } from "@playwright/test";
+import { gotoProducts, signUpWithStorefront, uploadFixture } from "../helpers";
+
+test("e2e_import_cancel_no_trace", async ({ page }) => {
+  await signUpWithStorefront(page);
+  await gotoProducts(page);
+  await uploadFixture(page, "good.csv");
+
+  // The preview gate is up.
+  await expect(page.getByRole("heading", { name: "Import preview — good.csv" })).toBeVisible();
+  await expect(page.getByRole("button", { name: "2 to add" })).toBeVisible();
+
+  await page.getByRole("button", { name: "Cancel" }).click();
+
+  // Lands back on Products — still the empty state, no run recorded.
+  await expect(page.getByRole("heading", { level: 1, name: "Products" })).toBeVisible();
+  await expect(
+    page.getByText("No products yet. Bulk import is how product data gets in."),
+  ).toBeVisible();
+  await expect(page.getByText("No imports yet.")).toBeVisible();
+});

e2e/tests/import-errors.spec.ts

@@ -0,0 +1,41 @@
+// DoD scenario e2e_import_errors_actionable (SD-0002 §6.8): row-level errors are
+// actionable — line, column, message — at the preview gate AND on the run report
+// card (PUC-5), while the good rows still import.
+import { expect, test } from "@playwright/test";
+import { gotoProducts, signUpWithStorefront, uploadFixture } from "../helpers";
+
+test("e2e_import_errors_actionable", async ({ page }) => {
+  await signUpWithStorefront(page);
+  await gotoProducts(page);
+  await uploadFixture(page, "mixed-errors.csv");
+
+  // Preview tiles: two good products, one errored row.
+  await expect(
+    page.getByRole("heading", { name: "Import preview — mixed-errors.csv" }),
+  ).toBeVisible();
+  await expect(page.getByRole("button", { name: "2 to add" })).toBeVisible();
+  await page.getByRole("button", { name: "1 errors" }).click();
+
+  // The error table names the line, the column, and the problem (actionable, PUC-5).
+  const previewRow = page.locator(".errortable tbody tr");
+  await expect(previewRow).toHaveCount(1);
+  await expect(previewRow.locator("td").nth(0)).toHaveText("3");
+  await expect(previewRow.locator("td").nth(1)).toHaveText("Variant Price");
+  await expect(previewRow.locator("td").nth(2)).toContainText("is not a price");
+
+  // Good rows still import.
+  await page.getByRole("button", { name: "Import 2 products" }).click();
+
+  // Run detail: counts include the errored row, and the same error row persists.
+  await expect(page.getByRole("heading", { level: 1, name: "mixed-errors.csv" })).toBeVisible();
+  await expect(page.getByText("2 added · 0 updated · 1 rows in error")).toBeVisible();
+  const runRow = page.locator(".errortable tbody tr");
+  await expect(runRow).toHaveCount(1);
+  await expect(runRow.locator("td").nth(0)).toHaveText("3");
+  await expect(runRow.locator("td").nth(1)).toHaveText("Variant Price");
+  await expect(runRow.locator("td").nth(2)).toContainText("is not a price");
+
+  // The catalog gained the two good products.
+  await gotoProducts(page);
+  await expect(page.getByRole("heading", { level: 1, name: "Products · 2" })).toBeVisible();
+});

e2e/tests/import-file-rejected.spec.ts

@@ -0,0 +1,25 @@
+// DoD scenario e2e_import_file_rejected (SD-0002 §6.8): a file-level rejection
+// (PUC-5a) renders in place on the upload screen, the picker stays live for a
+// retry, and nothing is recorded — no products, no run.
+import { expect, test } from "@playwright/test";
+import { gotoProducts, signUpWithStorefront, uploadFixture } from "../helpers";
+
+test("e2e_import_file_rejected", async ({ page }) => {
+  await signUpWithStorefront(page);
+  await gotoProducts(page);
+  await uploadFixture(page, "missing-title.csv");
+
+  // The rejection renders in place, naming the missing column.
+  await expect(page.getByText("That file can't be imported")).toBeVisible();
+  await expect(page.getByText("missing the required column 'Title'")).toBeVisible();
+
+  // The picker is live again for a retry.
+  await expect(page.locator('input[type="file"]')).toBeEnabled();
+
+  // No trace: still the empty catalog, and no run recorded.
+  await gotoProducts(page);
+  await expect(
+    page.getByText("No products yet. Bulk import is how product data gets in."),
+  ).toBeVisible();
+  await expect(page.getByText("No imports yet.")).toBeVisible();
+});

e2e/tests/import-preview-confirm.spec.ts

@@ -0,0 +1,49 @@
+// DoD scenario e2e_import_preview_confirm (SD-0002 §6.8): the happy path end to
+// end — sign up, empty catalog, upload good.csv, preview gate (PUC-2/3), confirm,
+// run report card, and the catalog + history reflecting the import. Subsumes the
+// Task-15 harness smoke (sign-up journey + products empty state).
+import { expect, test } from "@playwright/test";
+import { gotoProducts, signUpWithStorefront, STOREFRONT_NAME, uploadFixture } from "../helpers";
+
+test("e2e_import_preview_confirm", async ({ page }) => {
+  await signUpWithStorefront(page);
+
+  // Admin topbar: storefront identity + the signed-in account chip (ex-smoke).
+  await expect(page.locator(".storeid__name")).toHaveText(STOREFRONT_NAME);
+  await expect(page.getByRole("button", { name: "Sign out" })).toBeVisible();
+
+  await gotoProducts(page);
+
+  // Empty state + the import affordances (SD-0002 §5.2, ex-smoke).
+  await expect(
+    page.getByText("No products yet. Bulk import is how product data gets in."),
+  ).toBeVisible();
+  await expect(page.getByRole("link", { name: "Download sample CSV" })).toBeVisible();
+
+  await uploadFixture(page, "good.csv");
+
+  // Preview (§5.4): summary tiles + the file's name in the heading.
+  await expect(page.getByRole("heading", { name: "Import preview — good.csv" })).toBeVisible();
+  await expect(page.getByRole("button", { name: "2 to add" })).toBeVisible();
+  await expect(page.getByRole("button", { name: "0 errors" })).toBeVisible();
+
+  // Drill in: open star-tee's diff row and see field-level detail (the S-variant SKU).
+  const starTee = page.locator(".difflist__item", { hasText: "star-tee" });
+  await starTee.locator("summary").click();
+  await expect(starTee.getByText("WG-TEE-S")).toBeVisible();
+
+  // Consent gate (PUC-3): confirm the import.
+  await page.getByRole("button", { name: "Import 2 products" }).click();
+
+  // Run detail (§5.5): report card with the file name, counts, and status.
+  await expect(page.getByRole("heading", { level: 1, name: "good.csv" })).toBeVisible();
+  await expect(page.getByText("2 added · 0 updated · 0 rows in error")).toBeVisible();
+  await expect(page.getByText("Complete", { exact: true })).toBeVisible();
+
+  // Back on Products: the catalog count and exactly one history row for this run.
+  await gotoProducts(page);
+  await expect(page.getByRole("heading", { level: 1, name: "Products · 2" })).toBeVisible();
+  const rows = page.locator(".datatable tbody tr");
+  await expect(rows).toHaveCount(1);
+  await expect(rows.first().getByRole("link", { name: "good.csv" })).toBeVisible();
+});

e2e/tests/roundtrip-noop.spec.ts

@@ -0,0 +1,30 @@
+// DoD scenario e2e_roundtrip_noop (SD-0002 §6.8, PUC-10): exporting then
+// re-importing the unmodified file previews as all-unchanged with the import
+// action disabled and the "Nothing to change" note.
+import { expect, test } from "@playwright/test";
+import { exportCatalog, gotoProducts, importGoodCsv, signUpWithStorefront } from "../helpers";
+
+test("e2e_roundtrip_noop", async ({ page }) => {
+  await signUpWithStorefront(page);
+  await gotoProducts(page);
+  await importGoodCsv(page);
+  await gotoProducts(page);
+
+  // Export the catalog, then re-import the unmodified file.
+  const { path } = await exportCatalog(page, "All products");
+  await page.getByRole("link", { name: "Import products" }).first().click();
+  await expect(page.getByRole("heading", { name: "Import products" })).toBeVisible();
+  await page.locator('input[type="file"]').setInputFiles(path);
+
+  // Preview: everything unchanged, nothing to add/update (PUC-10).
+  await expect(page.getByRole("button", { name: "2 unchanged" })).toBeVisible();
+  await expect(page.getByRole("button", { name: "0 to add" })).toBeVisible();
+  await expect(page.getByRole("button", { name: "0 to update" })).toBeVisible();
+
+  // The import action is disabled, with the no-op note.
+  const importBtn = page.getByRole("button", { name: /^Import 0 products$/ });
+  await expect(importBtn).toBeDisabled();
+  await expect(
+    page.getByText("Nothing to change — your catalog already matches this file"),
+  ).toBeVisible();
+});

frontend/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "wiggleverse-ecomm-frontend",
-  "version": "0.4.0",
+  "version": "0.6.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "wiggleverse-ecomm-frontend",
-      "version": "0.4.0",
+      "version": "0.6.0",
       "dependencies": {
         "react": "^18.3.1",
         "react-dom": "^18.3.1"

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "wiggleverse-ecomm-frontend",
   "private": true,
-  "version": "0.4.0",
+  "version": "0.6.0",
   "type": "module",
   "scripts": {
     "dev": "vite",

frontend/src/adminRouting.test.ts

@@ -0,0 +1,18 @@
+import { describe, expect, it } from "vitest";
+import { adminViewFor, hashFor, type AdminView } from "./adminRouting";
+
+const VIEWS: AdminView[] = [
+  { view: "home" }, { view: "products" }, { view: "import-upload" },
+  { view: "import-preview", draftId: 7 }, { view: "run-detail", runId: 12 },
+];
+
+describe("adminRouting", () => {
+  it("round-trips every view", () => {
+    for (const v of VIEWS) expect(adminViewFor(hashFor(v))).toEqual(v);
+  });
+  it("defaults junk to home/products", () => {
+    expect(adminViewFor("")).toEqual({ view: "home" });
+    expect(adminViewFor("#/nonsense")).toEqual({ view: "home" });
+    expect(adminViewFor("#/products/imports/drafts/abc")).toEqual({ view: "products" });
+  });
+});

frontend/src/adminRouting.ts

@@ -0,0 +1,31 @@
+// Hash routing for admin sections (SD-0002 §5). The URL is the durable handle on a
+// section (PUC-8: run detail can be left and returned to); the SD-0001 entry-routing
+// rule (routing.ts) still decides whether the admin renders at all.
+export type AdminView =
+  | { view: "home" }
+  | { view: "products" }
+  | { view: "import-upload" }
+  | { view: "import-preview"; draftId: number }
+  | { view: "run-detail"; runId: number };
+
+export function adminViewFor(hash: string): AdminView {
+  const parts = hash.replace(/^#\/?/, "").split("/").filter(Boolean);
+  if (parts[0] !== "products") return { view: "home" };
+  if (parts.length === 1) return { view: "products" };
+  if (parts[1] === "import" && parts.length === 2) return { view: "import-upload" };
+  if (parts[1] === "imports" && parts[2] === "drafts" && /^\d+$/.test(parts[3] ?? ""))
+    return { view: "import-preview", draftId: Number(parts[3]) };
+  if (parts[1] === "imports" && parts[2] === "runs" && /^\d+$/.test(parts[3] ?? ""))
+    return { view: "run-detail", runId: Number(parts[3]) };
+  return { view: "products" };
+}
+
+export function hashFor(v: AdminView): string {
+  switch (v.view) {
+    case "home": return "#/";
+    case "products": return "#/products";
+    case "import-upload": return "#/products/import";
+    case "import-preview": return `#/products/imports/drafts/${v.draftId}`;
+    case "run-detail": return `#/products/imports/runs/${v.runId}`;
+  }
+}

frontend/src/api.ts

@@ -15,7 +15,7 @@ export interface VerifyResult {
   created: boolean;
 }
 
-async function errorOf(resp: Response): Promise<ApiError> {
+export async function errorOf(resp: Response): Promise<ApiError> {
   try {
     const body = await resp.json();
     if (body && body.error) return body.error as ApiError;

frontend/src/productsApi.export.test.ts

@@ -0,0 +1,12 @@
+import { describe, expect, it } from "vitest";
+import { EXPORT_STATUSES, exportUrl } from "./productsApi";
+
+describe("export url", () => {
+  it("lists the four status filters with 'all' first", () => {
+    expect(EXPORT_STATUSES.map((s) => s.value)).toEqual(["all", "active", "draft", "archived"]);
+  });
+  it("builds the endpoint url with the status query", () => {
+    expect(exportUrl("all")).toBe("/api/products/export?status=all");
+    expect(exportUrl("archived")).toBe("/api/products/export?status=archived");
+  });
+});

frontend/src/productsApi.ts

@@ -0,0 +1,114 @@
+// Typed fetch wrappers for the /api/products/* surface (SD-0002 §6.4). Same
+// conventions as api.ts: same-origin, cookie session, §6.4 error envelope.
+import { errorOf, type ApiError } from "./api";
+
+export interface DiffSummary { adds: number; updates: number; unchanged: number; errors: number; }
+export interface Draft {
+  id: number; file_name: string; dialect: string;
+  summary: DiffSummary; unknown_columns: string[]; expires_at: string;
+}
+export type RecordKind = "add" | "update" | "unchanged" | "error";
+export interface RowErrorDetail { line: number; column: string | null; message: string; }
+export interface FieldChange { field: string; before: unknown; after: unknown; }
+export interface VariantEntry {
+  options: (string | null)[]; kind?: string;
+  set?: Record<string, unknown>; changes?: FieldChange[];
+}
+export interface ImageEntry { src: string; kind?: string; position?: number; alt_text?: string | null; changes?: FieldChange[]; }
+export interface DraftRecord {
+  handle: string; title: string; kind: RecordKind; variant_count: number;
+  detail: {
+    set?: Record<string, unknown>;
+    option_names?: (string | null)[];
+    changes?: FieldChange[];
+    variants?: VariantEntry[];
+    images?: ImageEntry[];
+    errors?: RowErrorDetail[];
+  };
+}
+export interface RunSummary {
+  id: number; file_name: string; dialect: string; created_at: string;
+  completed_at: string | null; status: string; by: string;
+  products_added: number; products_updated: number; rows_errored: number;
+}
+export interface RunDetail extends RunSummary {
+  errors: RowErrorDetail[];
+  image_progress: { done: number; total: number };
+  image_outcomes: unknown[];
+}
+export interface ProductsSummary {
+  product_count: number; image_problem_count: number; latest_run_id: number | null;
+}
+
+export type Result<T> = { ok: true; value: T } | { ok: false; error: ApiError; status: number };
+
+// One label rule for CSV dialects, shared by Products history / preview / run detail.
+export function dialectLabel(d: string): string {
+  return d === "canonical" ? "Canonical format" : d;
+}
+
+export type ExportStatus = "all" | "active" | "draft" | "archived";
+
+// PUC-9 status filter, 'all' first (the default). Labels drive the export menu.
+export const EXPORT_STATUSES: { value: ExportStatus; label: string }[] = [
+  { value: "all", label: "All products" },
+  { value: "active", label: "Active" },
+  { value: "draft", label: "Draft" },
+  { value: "archived", label: "Archived" },
+];
+
+// The export is a browser download (native save dialog + streaming), not a fetch
+// wrapper — so the API module contributes a URL builder, not a request().
+export function exportUrl(status: ExportStatus): string {
+  return `/api/products/export?status=${status}`;
+}
+
+async function request<T>(path: string, init?: RequestInit): Promise<Result<T>> {
+  const resp = await fetch(path, { credentials: "include", ...init });
+  if (!resp.ok) return { ok: false, error: await errorOf(resp), status: resp.status };
+  if (resp.status === 204) return { ok: true, value: undefined as T };
+  return { ok: true, value: (await resp.json()) as T };
+}
+
+export function getProductsSummary(): Promise<Result<ProductsSummary>> {
+  return request("/api/products/summary");
+}
+
+export function uploadImport(file: File): Promise<Result<Draft>> {
+  const body = new FormData();
+  body.append("file", file);
+  // No content-type header: the browser sets the multipart boundary.
+  return request("/api/products/imports", { method: "POST", body });
+}
+
+export function getDraft(id: number): Promise<Result<Draft>> {
+  return request(`/api/products/imports/drafts/${id}`);
+}
+
+export async function getDraftRecords(
+  id: number, kind?: RecordKind, limit = 100, offset = 0,
+): Promise<Result<DraftRecord[]>> {
+  const params = new URLSearchParams({ limit: String(limit), offset: String(offset) });
+  if (kind) params.set("kind", kind);
+  const resp = await request<{ records: DraftRecord[] }>(
+    `/api/products/imports/drafts/${id}/records?${params}`,
+  );
+  return resp.ok ? { ok: true, value: resp.value.records } : resp;
+}
+
+export function confirmDraft(id: number): Promise<Result<{ run_id: number }>> {
+  return request(`/api/products/imports/drafts/${id}/confirm`, { method: "POST" });
+}
+
+export function cancelDraft(id: number): Promise<Result<void>> {
+  return request(`/api/products/imports/drafts/${id}`, { method: "DELETE" });
+}
+
+export async function listRuns(): Promise<Result<RunSummary[]>> {
+  const resp = await request<{ runs: RunSummary[] }>("/api/products/imports/runs");
+  return resp.ok ? { ok: true, value: resp.value.runs } : resp;
+}
+
+export function getRun(id: number): Promise<Result<RunDetail>> {
+  return request(`/api/products/imports/runs/${id}`);
+}

frontend/src/screens/Admin.tsx

@@ -1,9 +1,16 @@
-// Admin shell (SD-0001 §5.4) — the storefront's stable home; honestly empty this release
-// (PUC-8; PUC-9 sign-out). Renders from /me alone: storefront name + signed-in email. No
-// zeroed metric tiles, no locked-feature teasers (OHM: Agency & Anti-Manipulation).
-// Visuals per the ui/designs export (hf-admin).
+// Admin shell (SD-0001 §5.4) — the storefront's stable home; the home view is honestly
+// empty this release (PUC-8; PUC-9 sign-out). Renders from /me alone: storefront name +
+// signed-in email. No zeroed metric tiles, no locked-feature teasers (OHM: Agency &
+// Anti-Manipulation). Visuals per the ui/designs export (hf-admin). SD-0002 §5 adds the
+// admin nav strip + hash-routed products section (adminRouting.ts).
+import { useEffect, useState } from "react";
+import { adminViewFor, type AdminView } from "../adminRouting";
 import { logout } from "../api";
 import { AccountChip, Banner, Eyebrow, Screen, TopBar } from "../ui/kit";
+import ImportPreview from "./products/ImportPreview";
+import ImportUpload from "./products/ImportUpload";
+import ProductsPage from "./products/ProductsPage";
+import RunDetail from "./products/RunDetail";
 
 interface Props {
   storefrontName: string;
@@ -13,6 +20,14 @@ interface Props {
 }
 
 export default function Admin({ storefrontName, email, welcome, onSignedOut }: Props) {
+  const [view, setView] = useState<AdminView>(adminViewFor(window.location.hash));
+
+  useEffect(() => {
+    const onHashChange = () => setView(adminViewFor(window.location.hash));
+    window.addEventListener("hashchange", onHashChange);
+    return () => window.removeEventListener("hashchange", onHashChange);
+  }, []);
+
   async function signOut() {
     await logout();
     onSignedOut();
@@ -32,27 +47,41 @@ export default function Admin({ storefrontName, email, welcome, onSignedOut }: P
         }
         right={<AccountChip email={email} onSignOut={signOut} />}
       />
+      <nav className="adminnav" aria-label="Admin sections">
+        <a className={`adminnav__item${view.view === "home" ? " adminnav__item--active" : ""}`} href="#/">
+          Overview
+        </a>
+        <a className={`adminnav__item${view.view !== "home" ? " adminnav__item--active" : ""}`} href="#/products">
+          Products
+        </a>
+      </nav>
       <main className="screen__main">
-        <div className="empty">
-          {welcome && (
-            <div style={{ marginBottom: 24, width: "100%" }}>
-              <Banner tone="info" title={welcome === "new" ? "Welcome to ecomm" : "Welcome back"}>
-                {welcome === "new"
-                  ? "A new account was created for this email."
-                  : "Signed in to your existing account."}
-              </Banner>
+        {view.view === "home" && (
+          <div className="empty">
+            {welcome && (
+              <div style={{ marginBottom: 24, width: "100%" }}>
+                <Banner tone="info" title={welcome === "new" ? "Welcome to ecomm" : "Welcome back"}>
+                  {welcome === "new"
+                    ? "A new account was created for this email."
+                    : "Signed in to your existing account."}
+                </Banner>
+              </div>
+            )}
+            <div className="empty__seal" aria-hidden="true">
+              <img src="/brand/mark-mono-gold.svg" width={36} height={36} alt="" />
             </div>
-          )}
-          <div className="empty__seal" aria-hidden="true">
-            <img src="/brand/mark-mono-gold.svg" width={36} height={36} alt="" />
+            <Eyebrow>Your storefront</Eyebrow>
+            <h1>{storefrontName}</h1>
+            <p className="empty__copy">
+              There's nothing to manage yet — and that's a finished state, not a missing one.
+              Catalog, orders, and settings will appear here as ecomm grows.
+            </p>
           </div>
-          <Eyebrow>Your storefront</Eyebrow>
-          <h1>{storefrontName}</h1>
-          <p className="empty__copy">
-            There's nothing to manage yet — and that's a finished state, not a missing one.
-            Catalog, orders, and settings will appear here as ecomm grows.
-          </p>
-        </div>
+        )}
+        {view.view === "products" && <ProductsPage />}
+        {view.view === "import-upload" && <ImportUpload />}
+        {view.view === "import-preview" && <ImportPreview draftId={view.draftId} />}
+        {view.view === "run-detail" && <RunDetail runId={view.runId} />}
       </main>
     </Screen>
   );

frontend/src/screens/products/ImportPreview.tsx

@@ -0,0 +1,393 @@
+// Import preview (SD-0002 §5.4) — the consent gate. Summary tiles filter a
+// drill-in diff list; the sticky footer carries confirm (PUC-3) / cancel (PUC-3a).
+// Diff glyphs pair with color, never color alone (§6.6).
+import { useEffect, useRef, useState } from "react";
+import {
+  cancelDraft,
+  confirmDraft,
+  dialectLabel,
+  getDraft,
+  getDraftRecords,
+  type Draft,
+  type DraftRecord,
+  type FieldChange,
+  type RecordKind,
+  type VariantEntry,
+} from "../../productsApi";
+import { Banner } from "../../ui/kit";
+
+const PAGE = 100;
+
+function fmt(v: unknown): string {
+  if (v === null || v === undefined) return "—";
+  if (Array.isArray(v)) return v.length ? v.join(", ") : "—";
+  if (typeof v === "boolean") return v ? "TRUE" : "FALSE";
+  return String(v);
+}
+
+function KindChip({ kind }: { kind: RecordKind }) {
+  return <span className={`kindchip kindchip--${kind}`}>{kind}</span>;
+}
+
+function SetLine({ field, value }: { field: string; value: unknown }) {
+  return (
+    <div className="diffchange">
+      <span className="diffchange__glyph--add">+ </span>
+      {field}: {fmt(value)}
+    </div>
+  );
+}
+
+function ChangeRow({ change }: { change: FieldChange }) {
+  return (
+    <div className="diffchange">
+      {change.field}: <span className="diffchange__glyph--del">− {fmt(change.before)}</span> →{" "}
+      <span className="diffchange__glyph--add">+ {fmt(change.after)}</span>
+    </div>
+  );
+}
+
+function variantLabel(v: VariantEntry): string {
+  const opts = v.options.filter((o): o is string => o != null);
+  return opts.length ? `Variant ${opts.join(" / ")}` : "Variant";
+}
+
+function RecordDetail({ record }: { record: DraftRecord }) {
+  const d = record.detail;
+  if (record.kind === "error") {
+    return (
+      <div>
+        {(d.errors ?? []).map((e, i) => (
+          <div className="diffchange" key={i}>
+            line {e.line}: {e.column != null && `'${e.column}' — `}
+            {e.message}
+          </div>
+        ))}
+      </div>
+    );
+  }
+  return (
+    <div>
+      {Object.entries(d.set ?? {}).map(([field, value]) => (
+        <SetLine key={field} field={field} value={value} />
+      ))}
+      {(d.changes ?? []).map((c, i) => (
+        <ChangeRow key={i} change={c} />
+      ))}
+      {(d.variants ?? []).map((v, i) => (
+        <div key={i}>
+          <div className="diffchange diffchange--head">
+            {variantLabel(v)}
+            {v.kind ? ` (${v.kind})` : ""}
+          </div>
+          {Object.entries(v.set ?? {}).map(([field, value]) => (
+            <SetLine key={field} field={field} value={value} />
+          ))}
+          {(v.changes ?? []).map((c, j) => (
+            <ChangeRow key={j} change={c} />
+          ))}
+        </div>
+      ))}
+      {(d.images ?? []).map((img, i) =>
+        img.kind && img.kind !== "add" ? (
+          <div key={i}>
+            <div className="diffchange diffchange--head">
+              image: {img.src} ({img.kind})
+            </div>
+            {(img.changes ?? []).map((c, j) => (
+              <ChangeRow key={j} change={c} />
+            ))}
+          </div>
+        ) : (
+          <div className="diffchange" key={i}>
+            <span className="diffchange__glyph--add">+ </span>image: {img.src}
+          </div>
+        ),
+      )}
+    </div>
+  );
+}
+
+function ErrorTable({ records }: { records: DraftRecord[] }) {
+  const rows = records.flatMap((r) => r.detail.errors ?? []);
+  if (rows.length === 0) return null;
+  return (
+    <table className="errortable">
+      <thead>
+        <tr>
+          <th>Line</th>
+          <th>Column</th>
+          <th>Problem</th>
+        </tr>
+      </thead>
+      <tbody>
+        {rows.map((e, i) => (
+          <tr key={i}>
+            <td>{e.line}</td>
+            <td>{e.column ?? "—"}</td>
+            <td>{e.message}</td>
+          </tr>
+        ))}
+      </tbody>
+    </table>
+  );
+}
+
+export default function ImportPreview({ draftId }: { draftId: number }) {
+  const [draft, setDraft] = useState<Draft | null>(null);
+  const [loadFail, setLoadFail] = useState<"gone" | "expired" | "failed" | null>(null);
+  const [filter, setFilter] = useState<RecordKind | null>(null);
+  const [records, setRecords] = useState<DraftRecord[] | null>(null);
+  const [recordsError, setRecordsError] = useState<"load" | "more" | null>(null);
+  const [hasMore, setHasMore] = useState(false);
+  const [moreBusy, setMoreBusy] = useState(false);
+  const [confirming, setConfirming] = useState(false);
+  const [cancelling, setCancelling] = useState(false);
+  const [stale, setStale] = useState(false);
+  const [nothingNote, setNothingNote] = useState(false);
+  const [confirmError, setConfirmError] = useState<string | null>(null);
+  // Generation counter for the records list: bumped on every page-0 (re)load, so a
+  // page-0 or show-more response that resolves after a tile/filter (or draft) switch
+  // is recognized as stale and dropped instead of clobbering/appending to the new list.
+  const recordsGen = useRef(0);
+
+  async function loadDraft() {
+    setLoadFail(null);
+    const resp = await getDraft(draftId);
+    if (!resp.ok) {
+      setLoadFail(resp.status === 404 ? "gone" : resp.status === 410 ? "expired" : "failed");
+      return;
+    }
+    setDraft(resp.value);
+  }
+  useEffect(() => {
+    // A new draft means a fresh consent gate — reset everything the old one set.
+    setFilter(null);
+    setStale(false);
+    setConfirmError(null);
+    setNothingNote(false);
+    setRecords(null);
+    setRecordsError(null);
+    setHasMore(false);
+    void loadDraft();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [draftId]);
+
+  function loadRecords(kind: RecordKind | null) {
+    recordsGen.current += 1;
+    const gen = recordsGen.current;
+    setRecords(null);
+    setRecordsError(null);
+    setHasMore(false);
+    void getDraftRecords(draftId, kind ?? undefined, PAGE, 0).then((resp) => {
+      if (gen !== recordsGen.current) return;
+      if (!resp.ok) {
+        setRecordsError("load");
+        return;
+      }
+      setRecords(resp.value);
+      setHasMore(resp.value.length === PAGE);
+    });
+  }
+  useEffect(() => {
+    if (!draft) return;
+    loadRecords(filter);
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [draft, draftId, filter]);
+
+  async function showMore() {
+    if (!records) return;
+    const gen = recordsGen.current;
+    setMoreBusy(true);
+    setRecordsError(null);
+    const resp = await getDraftRecords(draftId, filter ?? undefined, PAGE, records.length);
+    setMoreBusy(false);
+    // Filter/draft switched while this page was in flight — drop the stale page.
+    if (gen !== recordsGen.current) return;
+    if (!resp.ok) {
+      setRecordsError("more");
+      return;
+    }
+    setRecords((prev) => [...(prev ?? []), ...resp.value]);
+    setHasMore(resp.value.length === PAGE);
+  }
+
+  async function onConfirm() {
+    setConfirming(true);
+    setConfirmError(null);
+    const resp = await confirmDraft(draftId);
+    if (resp.ok) {
+      window.location.hash = `#/products/imports/runs/${resp.value.run_id}`;
+      return;
+    }
+    setConfirming(false);
+    if ((resp.status === 409 && resp.error.code === "preview_stale") || resp.status === 410) {
+      setStale(true);
+    } else if (resp.status === 409 && resp.error.code === "nothing_to_apply") {
+      setNothingNote(true);
+    } else {
+      setConfirmError(resp.error.message);
+    }
+  }
+
+  async function onCancel() {
+    setCancelling(true);
+    // PUC-3a — cancel even on draft-gone (404) still navigates home.
+    await cancelDraft(draftId);
+    window.location.hash = "#/products";
+  }
+
+  if (loadFail === "gone") {
+    return (
+      <Banner tone="attn" title="This preview is gone">
+        <a href="#/products">Back to Products</a>
+      </Banner>
+    );
+  }
+  if (loadFail === "expired") {
+    return (
+      <Banner tone="attn" title="This preview expired — upload the file again">
+        <a href="#/products/import">Upload the file again</a>
+      </Banner>
+    );
+  }
+  if (loadFail === "failed") {
+    return (
+      <Banner tone="attn" title="Couldn't load this preview">
+        Something went wrong on our side.{" "}
+        <button type="button" className="linklike" onClick={() => void loadDraft()}>
+          Retry
+        </button>
+      </Banner>
+    );
+  }
+  if (!draft) {
+    return (
+      <p className="note" role="status">
+        Loading…
+      </p>
+    );
+  }
+
+  const { summary } = draft;
+  const tiles: { kind: RecordKind; num: number; label: string }[] = [
+    { kind: "add", num: summary.adds, label: "to add" },
+    { kind: "update", num: summary.updates, label: "to update" },
+    { kind: "unchanged", num: summary.unchanged, label: "unchanged" },
+    { kind: "error", num: summary.errors, label: "errors" },
+  ];
+  const toApply = summary.adds + summary.updates;
+
+  return (
+    <div className="products">
+      <p className="note">
+        <a href="#/products">← Products</a>
+      </p>
+      <h1>Import preview — {draft.file_name}</h1>
+      <p className="note">{dialectLabel(draft.dialect)}</p>
+      {draft.unknown_columns.length > 0 && (
+        <Banner tone="info" title="Columns not imported">
+          {draft.unknown_columns.length > 8 ? (
+            <details>
+              <summary>{draft.unknown_columns.length} columns not imported</summary>
+              {draft.unknown_columns.join(", ")}
+            </details>
+          ) : (
+            draft.unknown_columns.join(", ")
+          )}
+        </Banner>
+      )}
+      <div className="tiles">
+        {tiles.map((t) => (
+          <button
+            key={t.kind}
+            type="button"
+            className={`tile tile--${t.kind}${filter === t.kind ? " tile--active" : ""}`}
+            aria-pressed={filter === t.kind}
+            onClick={() => setFilter(filter === t.kind ? null : t.kind)}
+          >
+            <span className="tile__num">{t.num.toLocaleString()}</span>
+            <span className="tile__label">{t.label}</span>
+          </button>
+        ))}
+      </div>
+      {filter === "error" && records && <ErrorTable records={records} />}
+      {recordsError === "load" ? (
+        <p className="note note--attn" role="alert">
+          Couldn't load these records.{" "}
+          <button type="button" className="linklike" onClick={() => loadRecords(filter)}>
+            Retry
+          </button>
+        </p>
+      ) : records === null ? (
+        <p className="note" role="status">
+          Loading…
+        </p>
+      ) : records.length === 0 ? (
+        <p className="note">Nothing to show here.</p>
+      ) : (
+        <div className="difflist">
+          {records.map((r, i) => (
+            <details className="difflist__item" key={`${r.handle}-${i}`}>
+              <summary>
+                <span className="difflist__handle">{r.handle}</span> · {r.title} ·{" "}
+                <KindChip kind={r.kind} /> · {r.variant_count}{" "}
+                {r.variant_count === 1 ? "variant" : "variants"}
+              </summary>
+              <RecordDetail record={r} />
+            </details>
+          ))}
+        </div>
+      )}
+      {hasMore && (
+        <p>
+          <button type="button" className="btn-secondary" disabled={moreBusy} onClick={() => void showMore()}>
+            {moreBusy ? "Loading…" : "Show more"}
+          </button>
+          {recordsError === "more" && (
+            <span className="note note--attn" role="alert">
+              Couldn't load more records.{" "}
+              <button type="button" className="linklike" onClick={() => void showMore()}>
+                Retry
+              </button>
+            </span>
+          )}
+        </p>
+      )}
+      <div className="sticky-footer" aria-live="polite">
+        {stale ? (
+          <Banner tone="attn" title="Your catalog changed since this preview — upload the file again">
+            <a href="#/products/import">Upload the file again</a>
+          </Banner>
+        ) : (
+          <>
+            <button
+              type="button"
+              className="btn-primary"
+              disabled={toApply === 0 || confirming || cancelling}
+              onClick={() => void onConfirm()}
+            >
+              {confirming ? "Importing…" : `Import ${toApply.toLocaleString()} products`}
+            </button>
+            <button
+              type="button"
+              className="btn-secondary"
+              disabled={confirming || cancelling}
+              onClick={() => void onCancel()}
+            >
+              Cancel
+            </button>
+            {(toApply === 0 || nothingNote) && (
+              <span className="note">Nothing to change — your catalog already matches this file</span>
+            )}
+            {confirmError && (
+              <span className="note note--attn" role="alert">
+                {confirmError}
+              </span>
+            )}
+          </>
+        )}
+      </div>
+    </div>
+  );
+}

frontend/src/screens/products/ImportUpload.tsx

@@ -0,0 +1,60 @@
+// Import — upload (SD-0002 §5.3). Selecting a file starts upload + validation
+// immediately (PUC-2); file-level rejections (PUC-5a) render in place with the
+// picker live for retry. No notifications — errors render here.
+import { useRef, useState } from "react";
+import { uploadImport } from "../../productsApi";
+import { Banner } from "../../ui/kit";
+
+export default function ImportUpload() {
+  const [busy, setBusy] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const inputRef = useRef<HTMLInputElement>(null);
+
+  async function onPick(files: FileList | null) {
+    const file = files?.[0];
+    if (!file) return;
+    setBusy(true);
+    setError(null);
+    const resp = await uploadImport(file);
+    setBusy(false);
+    if (inputRef.current) inputRef.current.value = "";
+    if (!resp.ok) {
+      setError(resp.error.message);
+      return;
+    }
+    window.location.hash = `#/products/imports/drafts/${resp.value.id}`;
+  }
+
+  return (
+    <div className="products products--narrow">
+      <p className="note">
+        <a href="#/products">← Products</a>
+      </p>
+      <h1>Import products</h1>
+      {error && (
+        <Banner tone="attn" title="That file can't be imported">
+          {error}
+        </Banner>
+      )}
+      <label className={`dropzone${busy ? " dropzone--busy" : ""}`}>
+        <input
+          ref={inputRef}
+          type="file"
+          accept=".csv,text/csv"
+          disabled={busy}
+          onChange={(e) => void onPick(e.target.files)}
+        />
+        <span className="dropzone__title" aria-live="polite">
+          {busy ? "Validating…" : "Choose a CSV file"}
+        </span>
+        <span className="note">CSV, up to 5,000 rows</span>
+      </label>
+      <p className="note">
+        Works with the canonical format.{" "}
+        <a href="/api/products/sample.csv" download>
+          Download sample CSV
+        </a>
+      </p>
+    </div>
+  );
+}

frontend/src/screens/products/ProductsPage.tsx

@@ -0,0 +1,154 @@
+// Products page (SD-0002 §5.2) — the catalog's home: where imports start, exports
+// download, and history lives. SLICE-6 ships the export menu; the browsable list is #14's.
+import { useEffect, useState } from "react";
+import {
+  dialectLabel,
+  EXPORT_STATUSES,
+  exportUrl,
+  getProductsSummary,
+  listRuns,
+  type ProductsSummary,
+  type RunSummary,
+} from "../../productsApi";
+import { Banner } from "../../ui/kit";
+import { isExportEnabled } from "./exportMenu";
+
+const STATUS_LABELS: Record<string, string> = {
+  applying: "Importing…",
+  fetching_images: "Fetching images…",
+  complete: "Complete",
+  complete_with_problems: "Complete with problems",
+};
+
+export default function ProductsPage() {
+  const [summary, setSummary] = useState<ProductsSummary | null>(null);
+  const [runs, setRuns] = useState<RunSummary[] | null>(null);
+  const [failed, setFailed] = useState(false);
+
+  async function load() {
+    setFailed(false);
+    const [s, r] = await Promise.all([getProductsSummary(), listRuns()]);
+    if (!s.ok || !r.ok) {
+      setFailed(true);
+      return;
+    }
+    setSummary(s.value);
+    setRuns(r.value);
+  }
+  useEffect(() => {
+    void load();
+  }, []);
+
+  if (failed) {
+    return (
+      <Banner tone="attn" title="Couldn't load your products">
+        Something went wrong on our side.{" "}
+        <button type="button" className="linklike" onClick={() => void load()}>
+          Retry
+        </button>
+      </Banner>
+    );
+  }
+  if (!summary || !runs) {
+    return (
+      <p className="note" role="status">
+        Loading…
+      </p>
+    );
+  }
+
+  const empty = !isExportEnabled(summary.product_count);
+  return (
+    <div className="products">
+      <header className="products__header">
+        <h1>
+          Products
+          {!empty && <span className="products__count"> · {summary.product_count.toLocaleString()}</span>}
+        </h1>
+        <div className="products__actions">
+          {empty ? (
+            <div className="products__export">
+              <button type="button" className="btn-secondary" disabled>
+                Export
+              </button>
+              <span className="note">Export arrives when you have products</span>
+            </div>
+          ) : (
+            <details className="products__export menu">
+              <summary className="btn-secondary" role="button">
+                Export
+              </summary>
+              <ul className="menu__list">
+                {EXPORT_STATUSES.map((s) => (
+                  <li key={s.value}>
+                    {/* A real download: the browser navigates to the streamed
+                        endpoint and saves the attachment (PUC-9). */}
+                    <a className="menu__item" href={exportUrl(s.value)} download>
+                      {s.label}
+                    </a>
+                  </li>
+                ))}
+              </ul>
+            </details>
+          )}
+          <a className="btn-primary" href="#/products/import">
+            Import products
+          </a>
+        </div>
+      </header>
+      {empty ? (
+        <div className="empty">
+          <p className="empty__copy">No products yet. Bulk import is how product data gets in.</p>
+          <a className="btn-primary" href="#/products/import">
+            Import products
+          </a>
+          <p className="note">
+            <a href="/api/products/sample.csv" download>
+              Download sample CSV
+            </a>
+          </p>
+        </div>
+      ) : (
+        <p className="note">Your catalog is loaded. The browsable product list arrives with an upcoming release.</p>
+      )}
+      <section className="products__history">
+        <h2>Import history</h2>
+        {runs.length === 0 ? (
+          <p className="note">No imports yet.</p>
+        ) : (
+          <table className="datatable">
+            <thead>
+              <tr>
+                <th>Date</th><th>File</th><th>Dialect</th><th>Added</th><th>Updated</th><th>Errors</th><th>Status</th>
+              </tr>
+            </thead>
+            <tbody>
+              {runs.map((r) => (
+                <tr
+                  key={r.id}
+                  className="datatable__rowlink"
+                  onClick={() => {
+                    window.location.hash = `#/products/imports/runs/${r.id}`;
+                  }}
+                >
+                  <td>{new Date(r.created_at).toLocaleString()}</td>
+                  <td>
+                    {/* Anchor = the keyboard/SR path (§6.6); the row onClick stays as a
+                        mouse convenience. Both set the same hash, so the double fire on
+                        an anchor click is idempotent. */}
+                    <a href={`#/products/imports/runs/${r.id}`}>{r.file_name}</a>
+                  </td>
+                  <td>{dialectLabel(r.dialect)}</td>
+                  <td>{r.products_added}</td>
+                  <td>{r.products_updated}</td>
+                  <td>{r.rows_errored}</td>
+                  <td>{STATUS_LABELS[r.status] ?? r.status}</td>
+                </tr>
+              ))}
+            </tbody>
+          </table>
+        )}
+      </section>
+    </div>
+  );
+}

frontend/src/screens/products/RunDetail.tsx

@@ -0,0 +1,93 @@
+// Run detail (SD-0002 §5.5) — report card for a completed or in-progress import run.
+// NO images section this slice (SLICE-7). PUC-4/5/8.
+import { useEffect, useState } from "react";
+import { dialectLabel, getRun, type RunDetail as RunDetailType } from "../../productsApi";
+import { Banner } from "../../ui/kit";
+
+const STATUS_LABELS: Record<string, string> = {
+  applying: "Importing…",
+  fetching_images: "Fetching images…",
+  complete: "Complete",
+  complete_with_problems: "Complete with problems",
+};
+
+export default function RunDetail({ runId }: { runId: number }) {
+  const [run, setRun] = useState<RunDetailType | null>(null);
+  const [loadFail, setLoadFail] = useState<"gone" | "failed" | null>(null);
+
+  async function load() {
+    setLoadFail(null);
+    const resp = await getRun(runId);
+    if (!resp.ok) {
+      setLoadFail(resp.status === 404 ? "gone" : "failed");
+      return;
+    }
+    setRun(resp.value);
+  }
+  useEffect(() => {
+    void load();
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [runId]);
+
+  if (loadFail === "gone") {
+    return (
+      <Banner tone="attn" title="No such import run">
+        <a href="#/products">← Products</a>
+      </Banner>
+    );
+  }
+  if (loadFail === "failed") {
+    return (
+      <Banner tone="attn" title="Couldn't load this import run">
+        Something went wrong on our side.{" "}
+        <button type="button" className="linklike" onClick={() => void load()}>
+          Retry
+        </button>
+      </Banner>
+    );
+  }
+  if (!run) {
+    return (
+      <p className="note" role="status">
+        Loading…
+      </p>
+    );
+  }
+
+  return (
+    <div className="products">
+      <p className="note">
+        <a href="#/products">← Products</a>
+      </p>
+      <h1>{run.file_name}</h1>
+      <p className="note">
+        Imported {new Date(run.created_at).toLocaleString()} by {run.by} · {dialectLabel(run.dialect)}
+      </p>
+      <p className="note">
+        {run.products_added} added · {run.products_updated} updated · {run.rows_errored} rows in
+        error
+      </p>
+      <p className="note">{STATUS_LABELS[run.status] ?? run.status}</p>
+      {run.errors.length > 0 && (
+        <table className="errortable">
+          <thead>
+            <tr>
+              <th>Line</th>
+              <th>Column</th>
+              <th>Problem</th>
+            </tr>
+          </thead>
+          <tbody>
+            {run.errors.map((e, i) => (
+              <tr key={i}>
+                <td>{e.line}</td>
+                <td>{e.column ?? "—"}</td>
+                <td>{e.message}</td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      )}
+    </div>
+  );
+}

frontend/src/screens/products/exportMenu.test.ts

@@ -0,0 +1,19 @@
+import { describe, expect, it } from "vitest";
+import { EXPORT_STATUSES, exportUrl } from "../../productsApi";
+import { isExportEnabled } from "./exportMenu";
+
+describe("export menu", () => {
+  it("disables export for an empty catalog and enables it once there are products", () => {
+    expect(isExportEnabled(0)).toBe(false);
+    expect(isExportEnabled(3)).toBe(true);
+  });
+
+  it("builds the four status download URLs, 'all' first", () => {
+    expect(EXPORT_STATUSES.map((s) => exportUrl(s.value))).toEqual([
+      "/api/products/export?status=all",
+      "/api/products/export?status=active",
+      "/api/products/export?status=draft",
+      "/api/products/export?status=archived",
+    ]);
+  });
+});

frontend/src/screens/products/exportMenu.ts

@@ -0,0 +1,11 @@
+// Pure logic behind the Products page Export menu (SD-0002 §5.2, PUC-9). The
+// status list + URL builder live in productsApi.ts (re-used by the component);
+// this is the one decision the menu turns on — whether export is offered at all.
+// The disclosure JSX is verified by the E2E suite, matching SLICE-2/3's pattern
+// of pure-logic unit tests + E2E for screens.
+
+// Export is offered only when the catalog has products (PUC-9: an empty catalog
+// shows a disabled button + note instead).
+export function isExportEnabled(count: number): boolean {
+  return count > 0;
+}

frontend/src/styles/index.css

@@ -5,3 +5,4 @@
 @import "./tokens-typography.css";
 @import "./tokens-spacing.css";
 @import "./app.css";
+@import "./products.css";

frontend/src/styles/products.css

@@ -0,0 +1,303 @@
+/* Products section (SD-0002 §5) — admin nav strip, the catalog's home page, and the
+   import-flow primitives (dropzone, tiles, difflist — Tasks 12–14 consume these).
+   Same language as app.css: dark ground, glass chrome, hairline borders, small lifts. */
+
+/* Status accents (SD-0002 design bundle): add / update / error. */
+:root {
+  --st-add: #1F8A5B;
+  --st-update: #B5830F;
+  --st-error: #C2513E;
+}
+
+/* ── admin nav: horizontal strip under the topbar ───────────────────────────── */
+.adminnav {
+  flex: 0 0 auto;
+  display: flex;
+  gap: 26px;
+  padding: 0 36px;
+  border-bottom: 1px solid var(--border-soft);
+  background: rgba(9, 12, 34, .35);
+}
+.adminnav__item {
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-medium);
+  font-size: 14px;
+  color: var(--text-on-dark-mute);
+  text-decoration: none;
+  padding: 13px 2px 11px;
+  border-bottom: 2px solid transparent;
+  transition: color var(--dur-fast) var(--ease);
+}
+.adminnav__item:hover { color: var(--wv-starlight); }
+.adminnav__item--active { color: var(--wv-starlight); border-bottom-color: var(--wv-gold); }
+
+/* ── products page frame ────────────────────────────────────────────────────── */
+/* margin-bottom auto pins the page to the top of the centered .screen__main. */
+.products { width: 100%; max-width: 880px; margin-bottom: auto; }
+.products--narrow { max-width: 560px; }
+
+.products__header {
+  display: flex;
+  justify-content: space-between;
+  align-items: baseline;
+  gap: 16px;
+  margin-bottom: 28px;
+}
+.products__header h1 {
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-bold);
+  letter-spacing: var(--tracking-display);
+  font-size: 28px;
+  line-height: 1.1;
+  margin: 0;
+}
+.products__count { color: var(--text-on-dark-mute); font-weight: var(--weight-medium); }
+.products__actions { display: flex; gap: 12px; align-items: center; }
+/* Disabled Export + its visible "no products yet" caption, stacked (empty catalog). */
+.products__export { display: flex; flex-direction: column; gap: 4px; align-items: center; }
+.products__export .note { font-size: 11.5px; }
+
+/* Export status menu (SD-0002 §5.2 — PUC-9). A native <details> disclosure so
+   it's keyboard-accessible with no extra JS (§6.6). Tokens align with the design
+   bundle (--surface-raised / --border-card / --radius-panel); the fallbacks keep
+   it working regardless. */
+.products__export.menu {
+  position: relative;
+  display: inline-block;
+}
+.products__export.menu > summary {
+  list-style: none;
+  cursor: pointer;
+}
+.products__export.menu > summary::-webkit-details-marker {
+  display: none;
+}
+.menu__list {
+  position: absolute;
+  right: 0;
+  z-index: 10;
+  margin: 0.25rem 0 0;
+  padding: 0.25rem;
+  list-style: none;
+  background: var(--surface-raised, #fff);
+  border: 1px solid var(--border-card, #d8d3c8);
+  border-radius: var(--radius-panel, 8px);
+  box-shadow: var(--shadow-soft, 0 6px 20px rgba(0, 0, 0, 0.12));
+  min-width: 10rem;
+}
+.menu__item {
+  display: block;
+  padding: 0.5rem 0.75rem;
+  border-radius: var(--radius-sm, 6px);
+  text-decoration: none;
+  color: var(--text-on-dark-soft, inherit);
+  font-family: var(--wv-font-display);
+  font-size: 14px;
+}
+.menu__item:hover,
+.menu__item:focus {
+  background: var(--surface-raised-hi, #f3efe7);
+  color: var(--wv-starlight);
+}
+.products .btn-primary { width: auto; text-decoration: none; }
+.products .empty { margin: 24px auto 0; }
+
+.products__history { margin-top: 44px; }
+.products__history h2 {
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-semibold);
+  font-size: 17px;
+  letter-spacing: var(--tracking-display);
+  margin: 0 0 14px;
+}
+
+/* ── secondary button: outline twin of .btn-primary ─────────────────────────── */
+.btn-secondary {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  gap: .4em;
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-medium);
+  font-size: 15.5px;
+  line-height: 1;
+  padding: .85rem 1.4rem;
+  border-radius: var(--radius-pill);
+  border: var(--btn-border-w) solid var(--border-strong);
+  background: transparent;
+  color: var(--text-on-dark-soft);
+  cursor: pointer;
+  transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease),
+    transform var(--dur-fast) var(--ease);
+}
+.btn-secondary:hover:not(:disabled) { border-color: var(--wv-lilac); color: var(--wv-starlight); transform: var(--lift-1); }
+.btn-secondary:disabled { opacity: .45; cursor: not-allowed; }
+.btn-secondary:focus-visible { outline: 2px solid var(--focus-ring); outline-offset: 2px; }
+
+/* ── button that reads as a link (inline retry etc.) ────────────────────────── */
+.linklike {
+  background: none;
+  border: none;
+  padding: 0;
+  font: inherit;
+  color: var(--wv-lilac);
+  text-decoration: underline;
+  cursor: pointer;
+  transition: color var(--dur-fast) var(--ease);
+}
+.linklike:hover { color: var(--wv-gold); }
+
+/* ── data tables (import history; errortable shares the bones) ──────────────── */
+.datatable, .errortable {
+  width: 100%;
+  border-collapse: collapse;
+  font-size: 13.5px;
+}
+.datatable th, .errortable th {
+  text-align: left;
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-medium);
+  font-size: 12px;
+  letter-spacing: .06em;
+  text-transform: uppercase;
+  color: var(--text-on-dark-mute);
+  padding: 8px 12px;
+  border-bottom: 1px solid var(--border-card);
+}
+.datatable td, .errortable td {
+  padding: 11px 12px;
+  border-bottom: 1px solid var(--border-soft);
+  color: var(--text-on-dark-soft);
+}
+.datatable__rowlink { cursor: pointer; transition: background var(--dur-fast) var(--ease); }
+.datatable__rowlink:hover { background: var(--wv-lilac-08); }
+.errortable td:last-child { color: var(--st-error); }
+
+/* ── summary tiles (preview, Task 13) ───────────────────────────────────────── */
+.tiles { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
+.tile {
+  background: var(--surface-raised);
+  border: 1px solid var(--border-card);
+  border-radius: var(--radius-panel);
+  padding: 16px 18px;
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  align-items: flex-start;
+  font: inherit;
+  color: inherit;
+  text-align: left;
+  cursor: pointer;
+  transition: background var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
+}
+.tile:hover { background: var(--surface-raised-hi); }
+.tile--active { border-color: var(--wv-gold); }
+.tile__num {
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-bold);
+  font-size: 26px;
+  line-height: 1;
+  color: var(--text-on-dark-soft);
+}
+.tile__label { font-size: 12.5px; color: var(--text-on-dark-mute); }
+.tile--add .tile__num { color: var(--st-add); }
+.tile--update .tile__num { color: var(--st-update); }
+.tile--error .tile__num { color: var(--st-error); }
+
+/* ── diff list (preview records, Task 13) ───────────────────────────────────── */
+.difflist { list-style: none; margin: 0; padding: 0; }
+.difflist__item { padding: 12px 4px; border-bottom: 1px solid var(--border-soft); }
+.difflist__item > summary {
+  cursor: pointer;
+  font-size: 14px;
+  color: var(--text-on-dark-soft);
+  transition: color var(--dur-fast) var(--ease);
+}
+.difflist__item > summary:hover { color: var(--wv-starlight); }
+.difflist__item[open] > summary { margin-bottom: 8px; }
+.difflist__handle { font-family: ui-monospace, "SF Mono", Menlo, monospace; font-size: 12.5px; }
+.diffchange {
+  font-family: ui-monospace, "SF Mono", Menlo, monospace;
+  font-size: 12.5px;
+  line-height: 1.6;
+  color: var(--text-on-dark-soft);
+}
+.diffchange--head { color: var(--text-on-dark-mute); margin-top: 6px; }
+.diffchange__glyph--add { color: var(--st-add); }
+.diffchange__glyph--del { color: var(--st-error); }
+
+/* ── kind chip (preview record summaries, Task 13) ──────────────────────────── */
+.kindchip {
+  display: inline-block;
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-medium);
+  font-size: 11px;
+  letter-spacing: .06em;
+  text-transform: uppercase;
+  line-height: 1;
+  padding: 3px 9px 2px;
+  border-radius: var(--radius-pill);
+  border: 1px solid var(--border-strong);
+  color: var(--text-on-dark-mute);
+}
+.kindchip--add { color: var(--st-add); border-color: var(--st-add); }
+.kindchip--update { color: var(--st-update); border-color: var(--st-update); }
+.kindchip--error { color: var(--st-error); border-color: var(--st-error); }
+
+/* preview layout rhythm: tiles + errortable sit between header and difflist */
+.products .tiles { margin: 24px 0 18px; }
+.products .errortable { margin: 0 0 18px; }
+
+/* ── sticky confirm/cancel footer (preview, Task 13) ────────────────────────── */
+.sticky-footer {
+  position: sticky;
+  bottom: 0;
+  display: flex;
+  gap: 12px;
+  align-items: center;
+  padding: 14px 0;
+  border-top: 1px solid var(--border-soft);
+  background: var(--glass-sky);
+  backdrop-filter: blur(var(--glass-blur));
+}
+
+/* ── upload dropzone (Task 12) ──────────────────────────────────────────────── */
+.dropzone {
+  position: relative;
+  display: flex;
+  flex-direction: column;
+  align-items: center;
+  justify-content: center;
+  gap: 10px;
+  text-align: center;
+  padding: 48px 24px;
+  border: 2px dashed var(--border-strong);
+  border-radius: var(--radius-card);
+  cursor: pointer;
+  transition: border-color var(--dur-fast) var(--ease), background var(--dur-fast) var(--ease);
+}
+.dropzone:hover { border-color: var(--wv-lilac); background: var(--wv-lilac-08); }
+.dropzone--busy { opacity: .55; pointer-events: none; }
+.dropzone input[type="file"] {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  overflow: hidden;
+  clip: rect(0 0 0 0);
+  white-space: nowrap;
+}
+.dropzone__title {
+  display: block;
+  font-family: var(--wv-font-display);
+  font-weight: var(--weight-medium);
+  font-size: 17px;
+  color: var(--text-on-dark-soft);
+  margin-bottom: 2px;
+}
+
+/* ── small screens ──────────────────────────────────────────────────────────── */
+@media (max-width: 720px) {
+  .adminnav { padding: 0 20px; }
+  .tiles { grid-template-columns: repeat(2, 1fr); }
+  .products__header { flex-wrap: wrap; }
+}

scripts/e2e.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+# E2E browser gate (SD-0002 §6.8) — Playwright against a fresh local stack.
+# Not yet part of check.sh/CI: the CI runner has no browsers (§10.6 gap).
+set -euo pipefail
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$repo_root/e2e"
+if [ ! -d node_modules ]; then
+  npm install
+  npx playwright install chromium
+fi
+npx playwright test "$@"