Session 0018.0 (Wave 9): rewrite legacy session refs in transcript bodies + README scoping

- Rewrite every legacy `Session L` / `Session M.1` etc. reference inside
  transcript bodies to the numeric form (`Session 0012.0` / `Session 0013.1`),
  via a mechanical Python sed pass scoped to canonical-filename transcripts
  only (502 replacements across 39 files; 21 files in this published repo +
  18 sibling files in `~/git/ohm-infra/`). The §23 rename was originally
  filename-only — session 0018.0 reverses that and rewrites the bodies too,
  so cross-references inside a transcript match the filename you'd browse
  to. The mapping table (`A → 0001` … `N → 0014`) lives in
  `SESSION-PROTOCOL.md` §1 (also amended this session) for anyone hitting
  an old external link.

- Amend README.md:
  - New "Where the record begins" section noting OHM started with two
    vibe-coded prototypes (no transcripts; the discipline that produced this
    record didn't exist yet). The transcripts here begin at the
    spec-driven-development phase — not at the literal beginning of OHM.
  - Update the existing "Sessions 0001 through 0013 originally shipped
    under a letter-form naming" paragraph to reflect that body refs are
    now also in numeric form.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

0002/SESSION-0002.0-TRANSCRIPT-2026-05-25T19-30--2026-05-25T21-30.md

@@ -1,4 +1,4 @@
-# OHM deployment — Session B transcript
+# OHM deployment — Session 0002.0 transcript
 
 The full back-and-forth from the session in which Ben Stull (founder of
 Wiggleverse) deployed `ohm.wiggleverse.org` from zero on 2026-05-25 (rolling
@@ -28,7 +28,7 @@ repo (`wiggleverse/ohm-meta`), and freshly generated secrets.
   which was surfaced incidentally by `gcloud billing accounts list`.
 - A handful of personal directory names visible in an over-broad
   `find ~ -maxdepth 5` command the assistant ran while trying to locate a
-  prior "session A" transcript file. Ben told the assistant to stop reading
+  prior "session 0001.0" transcript file. Ben told the assistant to stop reading
   his home directory; the incidental observations are not published here.
 
 The transcript otherwise reproduces user messages verbatim and assistant
@@ -1321,8 +1321,8 @@ tabs → /settings/notifications).
 > is definitively my life's work (or the beginning of) and I'm so honored
 > that you did it for me. I didn't do shit...other than some K and some dot
 > connecting. Oh dear, this is going to get very, very, wobbly in this new
-> wiggly world :) The file name can be similar to session A's, except this
-> is session B. We
+> wiggly world :) The file name can be similar to session 0001.0's, except this
+> is session 0002.0. We
 
 (Message cut off at "We".)
 
@@ -1332,7 +1332,7 @@ tabs → /settings/notifications).
 
 Marked #12 complete. Then made a mistake: ran a too-broad
 `find ~ -maxdepth 5 -type f -name "*.md" | xargs grep -l -i "session [ab]"`
-to locate the prior "session A" transcript file. That scan returned matches
+to locate the prior "session 0001.0" transcript file. That scan returned matches
 that included unrelated personal directory names visible in the listing.
 Ben interrupted via system reminder telling the assistant to stop reading
 his life.
@@ -1365,7 +1365,7 @@ his life.
 >
 > Where do you want the file? Your message cut off at "We" — and I don't
 > want to guess the path from anything I shouldn't have looked at.
-> `~/git/ohm-infra/SESSION-B-TRANSCRIPT.md` would mirror what I saw in
+> `~/git/ohm-infra/SESSION-0002.0-TRANSCRIPT.md` would mirror what I saw in
 > passing, but tell me and I'll write it there.
 >
 > And — congratulations. The first OHM RFC for "Human" is a hell of a thing