fix(b-0260): make reindexer recursive — scan memory/ subdirectories

[AceHack]

Summary

• Root cause diagnosed: collectEntries in reindex-memory-md.ts used non-recursive readdir, silently excluding files in memory/ subdirectories (e.g. memory/observed-phenomena/). Both affected files had valid YAML frontmatter — the parity validator's gap-no-frontmatter label was a misleading diagnosis; the true cause was gap-subdirectory-not-scanned.
• Fix: extracted collectEntriesRecursive helper using readdir({ withFileTypes: true }), recursing into subdirs and storing paths relative to baseDir (e.g. observed-phenomena/file.md) — correct for both MEMORY.md markdown links and the parity-validator lookup set.
• Tests: 2 new tests added (scans subdirectories recursively, uses subdir-relative path for subdirectory entries). All 20/20 tests pass.
• Closes B-0260: all acceptance criteria met.

Parity result

Old-index entries:   672
Unique files:        672
Covered (ok):        672   ← was 670 (2 gaps before this fix)
No-frontmatter gap:  0     ← was 2
Missing (loss):      0

Full parity: all old-index files are covered by the generated index.

B-0260 acceptance criteria

• ✅ memory/MEMORY.md generated by tooling, not hand-edited
• ✅ Entry coverage parity verified: 672/672 covered
• ✅ Zero missing entries (no coverage loss)
• ✅ No intentional behavior changes requiring follow-up issues

Build gate

dotnet build -c Release → 0 warnings, 0 errors
bun test tools/memory/ → 20 pass, 0 fail
bun tools/memory/validate-memory-parity.ts → 672/672 covered, 0 gaps, 0 missing

Test plan

• bun test tools/memory/reindex-memory-md.test.ts — all 20 pass
• bun tools/memory/validate-memory-parity.ts — full parity confirmed
• dotnet build -c Release — 0 warnings, 0 errors
• B-0260 backlog item marked closed with closure notes
• BACKLOG.md regenerated (B-0260 shows [x])

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Fixes B-0260 by making the memory reindexer recursive so files in memory/ subdirectories (e.g., memory/observed-phenomena/) are included in MEMORY.md. Resolves the final 2 parity gaps (672/672 covered).

Changes:

• Replaces non-recursive collectEntries with a collectEntriesRecursive helper using readdir({ withFileTypes: true }), storing filename as a path relative to baseDir.
• Adds 2 tests covering recursive discovery and subdir-relative filename.
• Marks B-0260 closed (backlog row + regenerated docs/BACKLOG.md) and updates MEMORY.md heap-count footer (1103 → 1130).

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tools/memory/reindex-memory-md.ts	Recursive scan + relative-path filename for entries.
tools/memory/reindex-memory-md.test.ts	Adds two tests for recursive subdir scanning.
tools/memory/testdata/subdir/gamma_2026_05_14.md	Test fixture under a subdir.
memory/MEMORY.md	Footer heap-count updated to reflect new total.
docs/backlog/P1/B-0260-...md	Status → closed with closure notes.
docs/BACKLOG.md	Regenerated index entry checkbox for B-0260.

[chatgpt-codex-connector]

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