# Progress Log - challenger_m4_1

Last visited: 2026-10-09T08:22:30Z
Status: Completed — Verdict: REQUEST_CHANGES (Critical Bug Found in production_orchestrator.py:1170)

## Checklist
- [x] Record dispatch and read ORIGINAL_REQUEST.md, PROJECT.md, and worker_m4_assembly_1/handoff.md
- [x] Initialize/Update BRIEFING.md with M4 challenge mission
- [x] Run baseline test suites: `tests/test_production_pipeline_m4.py` (15/15 passed) and `tests/test_adversarial_m3_audio_engine.py` (6/6 passed)
- [x] Develop and execute empirical probe for Mode A vs Mode B Audio Duration Drift (5/5 passed in `tests/test_adversarial_m4_audio_concat_probe.py`)
- [x] Develop and execute empirical probe for Silent Clip & Missing Audio Track Resilience
- [x] Discover root cause of ffprobe path corruption in `production_orchestrator.py:1170`
- [x] Formulate empirical findings and challenge verdict: REQUEST_CHANGES
- [x] Update BRIEFING.md with final empirical results
- [x] Write 5-component handoff.md in challenger_m4_1 folder
- [ ] Send completion message to parent orchestrator (97faf5e5-a830-491c-b78c-2af12175badf)