fix: pre-landing review round — 8 auto-fixes + 8 accepted findings hardened

The ship review army (4 specialists + red-team + checklist, 29 findings)
produced 8 mechanical auto-fixes and 11 decisions; the accepted set:

- win32 slug parity completed: lib/bin-context.ts gains the remote-first
  outermost walk + degraded-cache self-heal the bash side got this wave —
  the two implementations now agree on the stray-marker live-bug shape,
  pinned by shared fixtures (multi-specialist 9/10 finding).
- probe honors the plan's bounded-read decision: 256KB prefix, extraction
  semantics mirrored from parseTranscriptJsonl so probe/prepare can never
  diverge on the same file (>1MB transcript test).
- policy normalize parity: bash normalize() now matches canonicalizeRemote
  on .git/-trailing and uppercase-.GIT shapes (7-shape corpus pinned two
  ways) — a deny for those shapes could previously slip the transcript gate.
- session-update reclaim is TOCTOU-safe (atomic mv-aside on both branches).
- settings-hook: unparseable settings.json errors instead of being replaced
  with {}; ensure-event keys on (event, source) so matcher changes update
  in place — never zero or two registrations.
- dot-only slug guard at both parse sites (hostile 'url = ..' can't escape
  projects/); enqueue tmp-file janitor (1h TTL, inside the drain lock);
  brain-sync .migrating never clobbered; drop-queue/status count .migrating;
  snapshot -o warning correct + surfaced in diff mode; version-bump test
  order-dependence removed; uninstall clears the advance stamp.

Deferred with record: slug heal-probe cost sentinel (P3 TODO), FF_OK
conflation (noted, misdiagnosis-only).

270 pass / 0 fail across the 10 touched suites.

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

bin/gstack-gbrain-repo-policy

@@ -92,14 +92,23 @@ normalize() {
   case "$head" in
     *:*) url=$(printf '%s' "$url" | sed 's|:|/|') ;;
   esac
+  # Lowercase BEFORE the suffix strips so a `.GIT` suffix still strips —
+  # parity with lib/gstack-memory-helpers' canonicalizeRemote, which strips
+  # `.git` case-insensitively. GitHub and most hosts are case-insensitive on
+  # paths anyway; collapsing avoids duplicate entries for "Foo/Bar" vs
+  # "foo/bar". (Parity is pinned by test/gbrain-repo-policy-client.test.ts:
+  # a key set through THIS normalize must be found via the canonicalized form
+  # memory-ingest passes to `get --batch`.)
+  url=$(printf '%s' "$url" | tr '[:upper:]' '[:lower:]')
+  # Strip trailing slash(es) FIRST, so ".git/" still loses its suffix (same
+  # order as canonicalizeRemote — slash-first, then .git, then re-strip).
+  while [ "${url%/}" != "$url" ]; do url="${url%/}"; done
   # Strip trailing .git
   url="${url%.git}"
-  # Strip trailing /
-  url="${url%/}"
-  # Lowercase the whole thing. GitHub and most hosts are case-insensitive on
-  # paths anyway; collapsing avoids duplicate entries for "Foo/Bar" vs
-  # "foo/bar".
-  printf '%s\n' "$url" | tr '[:upper:]' '[:lower:]'
+  # Re-strip trailing slash(es): a path remote ending in a `.git` directory
+  # component ("/repo/.git") exposes a new trailing slash once .git is gone.
+  while [ "${url%/}" != "$url" ]; do url="${url%/}"; done
+  printf '%s\n' "$url"
 }
 
 # ensure_file — create the policy file if missing, migrate if legacy.