TASK 56: the secret scan is done - and the history is clean

The release gate before the repo goes public. Scanned 432 reachable commits (all
branches, 35 tags, the reflog, refs/stash) + the 63 dangling commits git fsck still
holds + every tracked file in the worktree, for Google OAuth client secrets, API
keys/tokens (Polar OAT, ghp_, AKIA, Slack, Stripe, OpenAI), private-key headers,
assigned credentials, and any once-tracked CREDENTIALS.md / OAuthCredentials.cs /
MARCOM.md. Report format is commit + path + rule only - no matched value ever
reaches the screen.

Result: 4 hits, ALL false positives - README.md:79 is the doc snippet's
'ClientSecret = your-client-secret' placeholder, TokenStoreTests.cs:22 is a 9-char
test dummy. Nothing to rotate, no history rewrite. The three secret files were
never tracked.

Also recorded: the repo was ALREADY public when the scan ran (anonymous GET -> 200,
API private=false), so the gate came late - but nothing leaked. The creator still
owns the keep-it-public decision.

Method + verdict in TASKS/task-56-secret-scan.md; the reusable recipe in
MyMistakes.md -> 2026-10-22.

HANDOFF.md

@@ -251,7 +251,13 @@ Zombie entities deleted from the registry: `script.leak_strobe`, `script.doorbel
 - The judder reproduction take in the FAILING geometry (vertical 1080p60 first) is still outstanding — no
   fix until a take names the stage.
 - ⛔ Sudo password rotation pending (user; then update both `CREDENTIALS.md` password lines).
-- TASK 56 secret scan before `gramps/LlamaCasty` goes public.
+- ✅ **TASK 56 secret scan — DONE 2026-10-22, CLEAN.** 432 reachable commits (all branches, 35
+  tags, reflog, stash) + 63 dangling commits + the worktree: **0 real secrets**. 4 rule hits, all
+  false positives (`README.md:79` = the `your-client-secret` doc placeholder;
+  `TokenStoreTests.cs:22` = a 9-char test dummy). `CREDENTIALS.md`/`MARCOM.md`/
+  `Helpers/OAuthCredentials.cs` were never tracked. ⚠️ the repo was **already public** (anonymous
+  GET → 200, API `private = false`) when the scan ran — the gate came late, but nothing leaked.
+  Method + verdict: `TASKS/task-56-secret-scan.md`.
 - TASK 55 disk hygiene (`startup.log` uncapped — 23MB and growing every 5s).
 
 ## Tests