diff --git a/0055/SESSION-0055.0-TRANSCRIPT-2026-06-01T03-00--2026-06-01T03-35.md b/0055/SESSION-0055.0-TRANSCRIPT-2026-06-01T03-00--2026-06-01T03-35.md
new file mode 100644
index 0000000..523c5ba
--- /dev/null
+++ b/0055/SESSION-0055.0-TRANSCRIPT-2026-06-01T03-00--2026-06-01T03-35.md
@@ -0,0 +1,127 @@
+# Session 0055.0 — Transcript
+
+> Date: 2026-06-01
+> Start: 2026-06-01T03-00 (PST implied)
+> Goal (as it emerged): not launched as an OHM driver session — opened as a
+> conceptual Q&A comparing the OHM/flotilla self-hosted stack against a PaaS
+> like Vercel. It became a **flotilla SPEC design session**: the "which Vercel
+> wins could we adopt?" thread converged on per-PR preview environments, and
+> the operator asked for that to be specified.
+>
+> Outcome: **Added a fully-fleshed §19.2 candidate — "Per-PR preview
+> environments" — to `ohm-rfc-app-flotilla/SPEC.md`, committed on a branch,
+> merged `--no-ff` to `main`, and pushed to `origin`.** Two design decisions
+> were settled into the entry by the operator: (1) the §10 deploy audit trail
+> is **production-only** — neither per-PR previews nor PPE write to it; and (2)
+> previews use **SQLite only**, the same engine as production, which is exactly
+> what makes them cheap — no dual-engine/Postgres path. Along the way we
+> assessed (and rejected, for now) the idea of dual SQLite+Postgres support in
+> rfc-app.
+>
+> **Scope note (transcript-honest):** this is **pure-flotilla doc work with no
+> OHM actuation** — no deploy, no §13 record edit, no `ohm-rfc` operation. Per
+> SESSION-PROTOCOL the transcript expectation *softens* for exactly this case;
+> this transcript exists because the operator asked for one at session end. The
+> ID was therefore claimed at publish time (the protocol's late-claim path),
+> not at true session start.
+>
+> **Timestamp caveat:** the `03-00` start is anchored to the first commit of
+> the session (`912e828` at 03:03) and the preceding Q&A; the work actually
+> opened a few minutes earlier. A concurrent session published `0054`
+> (03-24/03-25) while this one was already in flight — expected under advisory
+> numbering; the `claim-session-id.sh` push allocated `0055` race-free.
+
+---
+
+## Pre-session state
+
+- `ohm-rfc-app-flotilla` at `main` = `70ba3b0` (flotilla v1.6.0 merged), clean
+  tree. SPEC.md at 1875 lines; §19.2 held the post-v1 candidate queue.
+- rfc-app checkout present at `~/projects/wiggleverse/rfc-app`
+  (HEAD `a3f48ba`), used read-only this session to assess the DB layer.
+- No preview-environment concept anywhere in flotilla; v1 has two long-lived
+  environments only (production VM + PPE, a single serialized lane).
+
+## Arc
+
+### Arc 1 — Q&A: the OHM/flotilla stack vs. Vercel
+Walked the advantages (ownership/no-lock-in, real persistent backend, flat
+predictable cost, secret discipline under operator control, mission-fit
+sovereignty, arbitrary architecture) against where Vercel wins (zero ops,
+push-deploy + preview envs + instant rollback, edge CDN, autoscaling, frontend
+DX). Bottom line: the app's *shape* (stateful backend, modest predictable
+traffic) is the opposite of Vercel's sweet spot; flagged Cloud Run as the
+"Vercel-like ergonomics without leaving the sovereignty model" middle path.
+
+### Arc 2 — Which Vercel wins to adopt
+Ranked the adoptable ones: per-PR previews (highest value), one-command
+rollback (flotilla half-has it via pinning), edge CDN via the existing
+Cloudflare relationship (cheapest win), atomic/zero-downtime deploys. Operator
+zeroed in on **per-PR deployments with synthetic data in a DB** — PPE's single
+lane can't do parallel/isolated review.
+
+### Arc 3 — Draft the spec
+Read SPEC §3/§5/§8/§10/§12/§13/§19.2 to match conventions, then added the
+**"Per-PR preview environments"** §19.2 candidate (placed after its cousin
+"Private-branch deploys"): problem statement, proposed `preview up/down/
+list/show` verb surface, runtime options (Cloud Run recommended over
+VM-containers), seeded-DB model, test-secret posture (zero real secret bytes —
+*strengthens* §3 invariant 1), the invariant-5 trigger tension, and the
+cross-section touchpoints.
+
+### Arc 4 — Decision: audit trail is production-only
+Explained the §10 deploy-history audit trail's purpose (append-only provenance:
+who/what/when/which-config for every prod deploy, secret-redacted; combined with
+`git log .rfc-app-version` + `gcloud secrets versions list` for full
+reconstruction) — and disambiguated it from the unrelated `flotilla audit`
+Patchwatch radar (§12.4). Operator decided: **previews and PPE never write the
+§10 trail — production only**, so `deploy log` stays high-signal. Recorded as
+**settled** in the entry.
+
+### Arc 5 — Dual SQLite+Postgres? Investigated, rejected for now
+Operator asked how hard it'd be to support both engines. Inspected rfc-app's DB
+layer: raw stdlib `sqlite3` (no ORM) in `backend/app/db.py` with a module-level
+singleton connection; **23 raw `.sql` migrations** (~1,300 lines) and **28 of
+43 app modules** issuing raw SQL. Quantified the SQLite-isms at the query sites
+(`datetime()`/`strftime` in 21 files, `lastrowid` in 12, `ON CONFLICT` in 8,
+`INSERT OR REPLACE/IGNORE` in 3, case-sensitive-`LIKE` hazard in 3), plus the
+structural mismatches (strict vs. dynamic typing, placeholder style, the
+singleton-conn-vs-pool concurrency model). Conclusion: dual-support is
+**medium-high effort + a permanent maintenance tax**, and rfc-app §4.2 already
+frames Postgres as a *future one-way migration*, not a dual-support goal.
+
+### Arc 6 — Decision: stay SQLite; previews are cheap because of it
+Operator: remove the Postgres framing entirely. Rewrote the candidate's DB
+paragraph — previews bake a seeded `.sqlite` (synthetic data) into the image
+and die with the container; prod and previews share **one engine**, which is
+precisely what makes per-PR previews cheap. No dual-engine/Postgres path to
+build or maintain; Postgres remains a hypothetical future one-way migration,
+never a prerequisite for previews.
+
+### Arc 7 — Ship
+Confirmed the entry internally consistent. Committed `912e828` on branch
+`spec/preview-environments-candidate`, merged `--no-ff` (`4c6781f`) to `main`,
+deleted the branch, pushed `5cf5ecd..4c6781f` to `origin/main`.
+
+## Artifacts
+
+- `ohm-rfc-app-flotilla/SPEC.md` §19.2 — new "Per-PR preview environments"
+  candidate (+85 lines). Merge commit `4c6781f` on `main`, pushed to origin.
+
+## What this session did NOT do
+
+- No OHM deploy, no §13 deployment-record edit, no `ohm-rfc` operation, no
+  rfc-app release. rfc-app was read-only (DB-layer assessment).
+- Did not start the preview feature's build — it remains a §19.2 candidate
+  that "earns its session" when concurrent PR review becomes PPE's bottleneck.
+- Did not act on the two open forks (Cloud Run vs VM-container runtime; the
+  invariant-5 trigger question) — left for the build session by design.
+
+## Handoff
+
+The preview-environments candidate is specced and on `main`. When it earns a
+build session, the two open decisions are runtime (Cloud Run strongly favored —
+also the on-ramp for a broader Cloud Run migration, gated on containerizing
+rfc-app) and the invariant-5 trigger (operator-typed `preview up --pr=N` first
+cut, deferring auto-on-PR to the hosted-flotilla shift). The DB and
+audit-trail questions are already settled (SQLite-only; production-only trail).
diff --git a/0055/SESSION-0055.0-TRANSCRIPT-2026-06-01T03-00--INPROGRESS.md b/0055/SESSION-0055.0-TRANSCRIPT-2026-06-01T03-00--INPROGRESS.md
deleted file mode 100644
index da34042..0000000
--- a/0055/SESSION-0055.0-TRANSCRIPT-2026-06-01T03-00--INPROGRESS.md
+++ /dev/null
@@ -1,15 +0,0 @@
-# Session 0055.0 — Transcript
-
-> Date: 2026-06-01
-> Start: 2026-06-01T03-00 (PST implied)
-> Status: **PLACEHOLDER — claimed at session start; finalized at session end.**
->
-> This file reserves session ID 0055. The driver replaces this body
-> with the full transcript before publishing, and renames the file to
-> its final SESSION-0055.0-TRANSCRIPT-2026-06-01T03-00--<end>.md form.
-
----
-
-## Launch prompt
-
-_(launch prompt not captured at claim time)_