R88.B — colibri-verification SKILL.md merkle_finalize failure mode (Verification)

1. PM authorization context

This slice ran under PM-authorized combined scope, granted in the explicit message:

“PM authorizes Option B: combined-scope re-execution. … You will now ship mirror resync + 2 surgical edits in a single PR.”

The dispatch packet had originally specified a feat-only scope (two surgical edits), with an IF BLOCKED protocol that triggered when Step 1 surfaced a pre-existing canonical/mirror drift. PM resolved the blocker by authorizing a combined scope that fuses the deferred R77.C-precedent mirror resync with the original two surgical edits in a single PR.

This verification document explicitly records the combined-scope authorization and confirms that the post-state matches the contract’s acceptance invariants.

2. Build / Lint / Test gate (CLAUDE.md §5)

All three CLAUDE.md §5 gates green at implement commit 9059bc65:

cd .worktrees/claude/r88-b-verification-skill-merkle-failure-mode
npm run build && npm run lint && npm test

Gate	Result	Evidence
`npm run build`	green	`tsc` clean; `postbuild` copy-migrations completed (6 migrations copied to dist)
`npm run lint`	green	`eslint src` exit 0; no warnings
`npm test`	green	47 suites passed, 47 total; 2406 tests passed, 2406 total; runtime 47.691 s

Note on test count: the memory file’s last-known count (1972) reflects a stale feature/r81-b-... worktree’s local snapshot. After fresh npm install in this worktree, Jest discovers all 47 suites that have shipped through R88.A; total is 2406 across 47 suites. No regressions; no new tests were added by this slice.

3. Doc-state gate

All 5 packet §4 doc-state invariants pass.

3.1 Files byte-identical

diff -q .agents/skills/colibri-verification/SKILL.md \
        .claude/skills/colibri-verification/SKILL.md

Result: empty output (return code 0). Both files are 338 lines.

3.2 Edit #1 — failures-table row (ERR_NO_RECORDS)

grep -c 'ERR_NO_RECORDS' \
        .agents/skills/colibri-verification/SKILL.md \
        .claude/skills/colibri-verification/SKILL.md

Result: 3 matches each (1 in failures table cell, 1 in caveat paragraph cell, 1 in subsequent caveat referencing the documented failure-mode label). Both files match. Invariant satisfied.

3.3 Edit #2 — Quick Reference caveat paragraph

grep -c 'opaque session/record binding' \
        .agents/skills/colibri-verification/SKILL.md \
        .claude/skills/colibri-verification/SKILL.md

Result: 1 match each. Both files match. Invariant satisfied.

3.4 “Symbolic Merkle” decorative-pattern naming

grep -c 'Symbolic Merkle' \
        .agents/skills/colibri-verification/SKILL.md \
        .claude/skills/colibri-verification/SKILL.md

Result: 2 matches each (1 in failures-table row Resolution column; 1 in Quick Reference caveat paragraph). Both files match. Invariant satisfied.

3.5 Investigation task UUID

grep -c '6f309f3a-7d22-4e2c-a02d-3a62fc46c834' \
        .agents/skills/colibri-verification/SKILL.md \
        .claude/skills/colibri-verification/SKILL.md

Result: 3 matches each (1 in failures-table row, 1 in caveat paragraph header, 1 in caveat paragraph body). Both files match. Invariant satisfied.

3.6 Memory file reference

grep -c 'feedback_audit_session_task_binding' \
        .agents/skills/colibri-verification/SKILL.md \
        .claude/skills/colibri-verification/SKILL.md

Result: 3 matches each (1 in failures-table row Cause column, 1 in Quick Reference caveat paragraph trailing sentence, 1 in changelog R88.B-stamp paragraph). Both files match. Invariant satisfied.

4. Post-state line counts

File	Pre-state (at base `2506bb44`)	Post-state (at implement `9059bc65`)	Delta
`.agents/skills/colibri-verification/SKILL.md`	333 lines	338 lines	+5
`.claude/skills/colibri-verification/SKILL.md`	296 lines	338 lines	+42

The canonical’s +5 is +2 (Edit #1 row appended to existing failures table) + +1 (Edit #2 single-paragraph blockquote) + +2 (R88.B-stamp changelog paragraph appended; the prior post-R83 paragraph had a 1-line edit that doesn’t change net line count). The mirror’s +42 is the resync delta to bring it from pre-R83 form to the new combined-scope state — this is expected and matches the audit §4 9-category divergence inventory plus the new content.

5. Combined-scope authorization audit trail

This verification doc explicitly notes — per PM authorization message — that the combined scope (mirror resync + surgical edits) IS the slice’s authorized scope as of 2026-05-07. The audit doc at 9437d85a had documented three options (A/B/C); PM authorized Option B with explicit guidance on order of operations.

The PR title and body reflect this combined scope:

PR title: feat(r88-b): mirror resync + document merkle_finalize ERR_NO_RECORDS failure mode (R88 Phase A continued, combined scope)
PR body: explicitly references “Combined-scope R88.B execution. Original two surgical edits to colibri-verification SKILL.md were blocked by pre-existing canonical-vs-mirror drift … PM authorized combined-scope: mirror resync + the 2 surgical edits in one PR.”

6. Out-of-scope changes confirmed absent

git diff origin/main -- . shows only:

4 new chain artefacts (docs/audits/, docs/contracts/, docs/packets/, docs/verification/)
2 modified SKILL.md files (.agents/skills/colibri-verification/SKILL.md + .claude/skills/colibri-verification/SKILL.md)

No other files modified. No src/, no tests/, no CLAUDE.md, no other .agents/skills/colibri-* or .claude/skills/colibri-* files. Out-of-scope criteria from contract §2.3 satisfied.

7. 5-step chain SHAs (confirmed)

Step	Output	SHA
1. Audit	`docs/audits/r88-b-verification-skill-merkle-failure-mode-audit.md`	`9437d85a`
2. Contract	`docs/contracts/r88-b-verification-skill-merkle-failure-mode-contract.md`	`b645ba6c`
3. Packet	`docs/packets/r88-b-verification-skill-merkle-failure-mode-packet.md`	`c1f70b51`
4. Implement	`.agents/skills/colibri-verification/SKILL.md` + `.claude/skills/colibri-verification/SKILL.md`	`9059bc65`
5. Verify	`docs/verification/r88-b-verification-skill-merkle-failure-mode-verification.md`	`<this commit>`

8. Acceptance criteria checklist (from PM authorization message §”Updated acceptance criteria”)

.agents/skills/colibri-verification/SKILL.md AND .claude/skills/colibri-verification/SKILL.md are byte-identical post-edit (diff -q returns empty)
Both files have the new failures-table row covering ERR_NO_RECORDS with reflection-recorded
Both files have the new Quick Reference caveat paragraph
Both files reference investigation task 6f309f3a-7d22-4e2c-a02d-3a62fc46c834
Both files reference feedback_audit_session_task_binding.md
Verification doc explicitly notes the combined-scope authorization (mirror resync + surgical edits) and cites this PM authorization message
No new lint warnings; build clean; tests green

All 7 PM-issued acceptance criteria satisfied.

9. Conclusion

R88.B combined-scope re-execution is verified complete. The pre-existing canonical/mirror drift surfaced in the audit is closed (R77.C-pattern resync); the two surgical doc edits are landed; both files are byte-identical and 338 lines; build/lint/test all green; no out-of-scope changes; the parked investigation task UUID is preserved in both files for future reference; and the audit_verify_chain { task_id } Phase 0 proof-grade workaround is named explicitly in both files for future executors who hit the same merkle_finalize ERR_NO_RECORDS symptom.

Step 5 of the 5-step chain. Slice ready for Colibri writeback (task_update { id: "9a104b4b-ee9e-434c-954c-801afdd91068", status: "done" } after thought_record { type: "reflection", task_id: "9a104b4b-…" }) and PR creation.