feat(trace): implement Phase 3 AI-Native Git Layer with TraceLogger, …

[redecon]

Description

This PR implements Phase 3: AI‑Native Git Layer (Full Traceability), building on Phase 1 (Handshake) and Phase 2 (Hook Middleware & Gatekeeper).

Key changes:

• TraceLogger.ts

  1. SHA‑256 content hashing utility
  2. Mutation classification (AST_REFACTOR vs INTENT_EVOLUTION)
  3. JSONL trace serialization to .orchestration/agent_trace.jsonl
  4. Intent‑based trace querying

• Tool Schema Update (write_to_file.ts)

  1. Added required intent_id parameter
  2. Added required mutation_class parameter (enum: AST_REFACTOR | INTENT_EVOLUTION)

• Test Suite (phase3-trace-logging.test.ts)
  10 comprehensive test cases covering hashing, classification, logging, and serialization

Documentation

• PHASE_3_IMPLEMENTATION.md – Feature overview and architecture
• PHASE_3_INTEGRATION_GUIDE.md – Post‑hook integration patterns and code examples
• PHASE_3_COMPLETION_REPORT.md – Full delivery report with compliance matrix

Test Procedure

Run:

pnpm vitest run tests/phase3-trace-logging.test.ts

Expected results:

• All 11 tests pass (1 handshake + 10 trace logging)
• Verified hashing, classification, logging, and serialization
• Trace entries include REQ‑ID and content_hash

Pre‑Submission Checklist

[x] Issue Linked

[x] Scope focused on Phase 3 deliverables

[x] Self‑review performed

[x] Unit tests added and passing

[x] Documentation updated (PHASE_3_* files)

[x] Contributor Guidelines reviewed