PR #1309 — Fleet Parity: Instruction File Preflight Check and Closed-Loop Receipt Verification

The Broader Goal at the End of the Previous PR

PR #1308 closed issue #342 by enforcing --cwd for Grok and -C for Codex, securing working-directory root containment across all autonomous dispatches. That left issue #347 as the final remaining open ticket from the original dogfooding-readiness fleet-parity cluster.

What Was Missing

Synlynk coordinates multi-agent workflows through instruction files (CLAUDE.md, GEMINI.md, AGENTS.md, GROK.md), where role boundaries, commit trailer requirements, and PR review protocols are defined.

However, the pipeline previously relied on unverified trust:

1. _preflight_dispatch() did not verify that a Core 4 agent's directive file was actually present and readable in an initialized repo. In issue #343, AGENTS.md was missing entirely, yet dispatches executed blindly.
2. Even when a file exists on disk, there was zero closed-loop verification that the spawned CLI actually read and internalized it. A job could report success while silently violating all repo conventions.

What Shipped

1. Instruction Version Extraction:
   • Added extract_instruction_version() and get_instruction_file_for_agent() in synlynk/instructions.py, extracting canonical version tokens from both synlynk:start and synlynk:harness markers.
2. Preflight Gate in _preflight_dispatch:
   • Fails closed with INSTRUCTION_FILE_MISSING if an instruction file for a Core 4 agent is absent in an initialized repo, unless explicitly bypassed with --force-harness / --force-agent.
3. Closed-Loop Instruction Receipt Protocol:
   • In synlynk/dispatch.py:_format_prompt_for_agent(), prompts the agent to echo SYNLYNK_INSTRUCTION_VERSION: <version> without revealing the version string in the prompt text.
   • The agent must genuinely inspect its loaded directive file to return the matching token.
4. Log Analysis & Advisory Signals:
   • In synlynk/jobs.py, added _check_instruction_receipt() to classify output as ok, mismatch, none, or absent.
   • Wired into _reconcile_jobs() and _reconcile_active_job() to record telemetry and emit advisory sentinel alerts on convention drift.
5. Comprehensive TDD Tests:
   • Added unit tests in tests/test_instructions.py, tests/test_dispatch.py, and tests/test_jobs.py.
   • All 499 tests in tests/test_synlynk.py pass cleanly.