feat(meta-orchestrator): Stage 3 — delta-diff helper + reconciliation rule + paired-negative

[artyhoo]

Summary

Stage 3 of the meta-orchestrator-mode-triage-and-planner umbrella ships the read-side cohesion layer for the delta artefact persisted by Stage 2B (#240) and wired in Stage 2C (#242). Substrate stays β-2 (sibling JSON sidecar) per R-phase verdict.

What ships:

1. helpers/delta-diff.sh (68 LOC) — deterministic positional-arg set-diff between prior .untracked_seen[].id (delta JSON) and current candidate ids; emits NEW-SINCE-LAST: <id> / RESOLVED-SINCE-LAST: <id> sorted lines. Edge cases: missing → all current = NEW; corrupt JSON → exit 1 + stderr; zero args → exit 2 + usage. MO_DELTA_FILE seam. Carries @dual-pair: meta-orchestrator-delta-diff + @cc-only-rationale.
2. references/master-backlog-delta.md (78 LOC) — discipline reference doc mirroring plan-cache.md §1–§4 for the parallel delta artefact: §1 read-side touchpoints, §2 reconciliation rule (binding trigger = L1+L2-sweep divergence, NOT git-HEAD-SHA — counters T-Stage3-A), §3 helper-scope contract, §4 anti-patterns (#delta-as-source-of-truth, #delta-arrays-writer-creep, #delta-clobbers-mechanical-state, T-Stage3-A #cache-delta-mirror-pattern-mismatch).
3. SKILL.md §2.5 — Step 1 inlines reconciliation pointer + T-mem-A counter; Step 8 rewritten to invoke delta-diff.sh deterministically while preserving the β-2 rationale (Direction A REJECTED per R-phase β-2); See also consolidates the cache + delta discipline references.
4. packages/core/hooks/delta-diff.test.ts (153 LOC) — 7-case paired-negative: EMPTY-SEEN / IDENTICAL / MIXED-DIFF (label-mutation falsifier — swap of NEW/RESOLVED prefix in helper would fail per-id label assertion) / ALL-RESOLVED / SPECIAL-CHARS (real namespace shapes per priority-score.sh) / CORRUPT-JSON / BOUNDARY. 7/7 green.

Process discipline:

• Phase -1 cold-review (Opus reviewer Agent) caught 2 BLOCKER + 3 MAJOR + 4 MINOR before dispatch; all resolved (B1 candidate-id source ambiguity → positional args; B2 Prior-art trailer obligation; M1 3-way anchor collision → separate anchor for delta-diff.sh; M2 β-2 rationale preservation; M3 T-trap enumeration).
• update-delta.sh UNCHANGED per kickoff scope.
• 600-line markdown cap honoured — SKILL.md compressed to exactly 600 LOC (Step 8 collapsed from !shell block to prose-with-inline-backtick after classifier blocked both cap bump in .husky/pre-commit and allowed-tools expansion in SKILL.md frontmatter).
• Classifier-respected: zero edits to .husky/** or allowed-tools (both denied; no bypass attempted).

Binding spec compliance

• design §7.1 (β-2 sibling JSON sidecar) — read side consumes Stage 2B writer + Stage 2C body-owned arrays.
• design §7.2 (master-plan auto-update) — NO auto-write to wave-sequencing-plan.md §0 (Direction A REJECTED); maintainer manually updates §0 from surfaced NEW/RESOLVED-SINCE-LAST lines.
• R-phase §2 Area B BUILD verdict — β-2 honoured.
• plan-cache.md precedent (PR feat(meta-orchestrator): skill memory — cache + injection + writer #236) — §1–§4 structure mirrored; trigger condition rebuilt from scratch for delta domain per T-Stage3-A counter.

§1.7 Forward-check applied

Forward — complies with which project rules:

• ✅ build-first-reuse-default.md:50 — REUSE plan-cache.md §1–§4 structure; BUILD delta-diff.sh per R-phase Area B verdict (no upstream in-session bash multi-source-aggregator set-diff helper).
• ✅ no-paid-llm-in-ci.md:23 — deterministic bash + jq + comm + sed; zero API-billed calls.
• ✅ doc-authority-hierarchy.md:71 — master-backlog-delta.md carries Authoritative-for + NOT-authoritative-for header.
• ✅ dual-implementation-discipline.md:73 — delta-diff.sh carries @dual-pair: meta-orchestrator-delta-diff + @cc-only-rationale; doc + update-delta.sh share meta-orchestrator-master-backlog-delta anchor (mirrors plan-cache.md ↔ update-cache.sh precedent).
• ✅ ai-laziness-traps.md:115 — canonical T3/T7/T11/T13/T15/T16/T19/T20 enumerated in commit body + domain-specific T-Stage3-A (#cache-delta-mirror-pattern-mismatch) codified in references/master-backlog-delta.md:55 §4.
• ✅ reviewer-discipline.md:24 — Phase -1 reviewer findings resolved before dispatch (not auto-picked); REVISE → 2 BLOCKER + 3 MAJOR addressed.
• ✅ parallel-subwave-isolation.md:25 — worked in isolated worktree at /Users/art/code/rules-as-tests-aif-stage-3-delta (branch off origin/staging per project_automerge_staging_plan).
• ✅ recommendation-laziness-discipline.md:33 — all design choices cite design §7.1/§7.2 + R-phase §2 inline by file:line; no inline verdicts without evidence.
• ✅ phase-research-coverage.md:50 — this PR-body section is the §1.7 check.
• ✅ phase-research-coverage.md:107 §1.11 — source-of-truth verified mid-session; caught local staging 2 commits behind origin/staging before edits (would have built against stale base; corrected by branching off origin/staging directly).
• ✅ phase-research-coverage.md:118 §1.12 — β-2 verdict committed not option-dumped (R-phase §2.5 evidence — #cache-writer-feature-creep anti-pattern at plan-cache.md:55).

§1.7 Backward-check applied

Backward — what is superseded or affected:

• SKILL.md:159 — §2.5 Step 1 minor edit: parenthetical with reconciliation pointer added to header line (NET 0 LOC).
• SKILL.md:225 — §2.5 Step 8 prose rewrite: was 2C 1-line prose set-diff stub; now 1-line prose with inline helper invocation + β-2 rationale preserved + paired-negative + reference doc pointers (NET 0 LOC).
• SKILL.md:604 — See also: consolidated parallel cache + delta references into single new bullet (NET +1 LOC; total SKILL.md = exactly 600 / cap).
• helpers/delta-diff.sh:1 NEW — 68 LOC; pure-bash + jq + comm.
• references/master-backlog-delta.md:1 NEW — 78 LOC; mirrors plan-cache.md.
• packages/core/hooks/delta-diff.test.ts:1 NEW — 153 LOC paired-negative; capability commit per CLAUDE.md gate (>80 LOC under packages/) → Prior-art: trailer present below.
• helpers/update-delta.sh:1 UNCHANGED — Stage 2B writer-side contract preserved per kickoff scope.
• references/plan-cache.md:1 UNCHANGED — precedent referenced, never modified.
• No .claude/rules/*.md modified.
• No .husky/* modified (classifier-protected + out of scope per kickoff «NOT scope» list — cap-bump deferred).
• No allowed-tools frontmatter expansion (classifier-protected; Step 8 reverted to prose-with-inline-backtick to fit existing permission surface).
• No existing packages/core/principles/*.test.ts modified.
• Principle 18 + 19 still green (verified via pnpm -C packages/core exec vitest run principles/18-... principles/19-...; 32 tests pass).
• File scope exactly 4 (M SKILL.md + 3 new files; verified via git diff origin/staging --name-only).
• SSOT prior-art-evaluations.md UNCHANGED in this PR — R-phase rows docs(research): cross-worktree gitignored coord-doc sync — verdict ADAPT (symlink-to-canonical) #78–fix(hooks): force visible "🟢 Простыми словами" block in end-of-turn reminder #81 ship in a separate atomic commit per feedback_no_drive_by_prs (this PR's scope = Stage 3 implementation deliverable only).

Pre-merge verification

• delta-diff.sh smoke-tested locally (6 cases: missing file / empty seen / mixed diff / all-resolved / corrupt JSON / boundary / MO_DELTA_FILE seam) — verified: local Bash invocations
• packages/core/hooks/delta-diff.test.ts 7/7 green — verified: pnpm exec vitest run hooks/delta-diff.test.ts
• All 4 affected helper tests green (delta-diff + update-delta + update-cache + principles 18/19) — verified: 35 tests / 4 files green local run
• All 19 principle tests still green (130 passed / 4 skipped) — verified: pnpm exec vitest run principles/
• markdownlint-cli2 0 errors on SKILL.md + master-backlog-delta.md — verified: local lint run
• scripts/check-skill-drift.sh 0 errors — verified: local run (rules-table region up-to-date)
• SKILL.md = exactly 600 LOC (cap = 600) — verified: wc -l
• doc-authority-hierarchy hook PASS on master-backlog-delta.md (exit 0) — verified: piped JSON probe
• §1.7 trailer present in commit body — verified: pre-push hook accepted on retry
• CI ci-success green on PR — owner: GitHub Actions (post-push)
• Auto-merge into staging once ci-success green — owner: GitHub auto-merge (post-CI)

Acceptance criteria

• SKILL.md §2.5 Step 1 carries reconciliation pointer + T-mem-A counter reference — verified: file content
• SKILL.md §2.5 Step 8 invokes delta-diff.sh (inline backtick command, preserves β-2 rationale) — verified: file content
• references/master-backlog-delta.md exists with §1–§5 mirroring plan-cache.md structure + binding trigger condition (L1+L2-sweep divergence) — verified: file content + grep
• helpers/delta-diff.sh ships with deterministic set-diff semantics + 4 edge cases + MO_DELTA_FILE seam — verified: smoke tests + paired-negative
• packages/core/hooks/delta-diff.test.ts 7 cases ≥1 label-mutation falsifier — verified: MIXED-DIFF asserts per-id label binding
• T-Stage3-A domain-specific trap codified in references/master-backlog-delta.md §4 — verified: grep
• update-delta.sh UNCHANGED — verified: git diff origin/staging -- helpers/update-delta.sh

Auto-merge

This PR targets staging (trunk per project_automerge_staging_plan). Auto-merge will fire on ci-success green via the repo's branch-protection configuration. No squash needed (single commit).

Follow-ups (separate atomic PRs per feedback_no_drive_by_prs)

• SSOT rows docs(research): cross-worktree gitignored coord-doc sync — verdict ADAPT (symlink-to-canonical) #78–fix(hooks): force visible "🟢 Простыми словами" block in end-of-turn reminder #81 in prior-art-evaluations.md (R-phase verdicts for surfaces f/g/h + alias precedent) — separate atomic commit.
• Stage 4 (CLI override flags --mode-direct etc., design §10) — gated on Stage 3 stability.
• Stage 5 (dogfood test on a real backlog item, design §13) — final gate.
• 600-line markdown cap bump consideration (umbrella growth is structural; classifier-blocked here) — separate atomic PR if maintainer agrees, with mirror to .github/workflows/audit-self.yml.