{
  "intent": "Split the 356-line _transcribe_diarize.py into media probing, clustering maths, and the diarization pipeline, all under the 250-line cap, moving every definition verbatim.",
  "scope": [
    "_transcribe_diarize.py 356 -> 164 (audio loading, classifier, embeddings, diarize_segments)",
    "New: _transcribe_media.py 143 (duration probing, ffmpeg transcode, temp cleanup)",
    "New: _transcribe_cluster.py 105 (linear resampling, cosine k-means)",
    "transcribe_fw.py: one import line re-pointed",
    "Non-goal: any behaviour change"
  ],
  "changes": [
    "Extracted _try_import, both duration probes, get_media_duration, the ffmpeg transcode and _cleanup_temp into _transcribe_media.py; _resample_linear, _kmeans_cosine and _run_kmeans_iterations into _transcribe_cluster.py. What remains in _transcribe_diarize.py is the pipeline: loading audio, loading the classifier, extracting embeddings, and diarize_segments.",
    "The dependency graph is a tree: _transcribe_media imports nothing local, _transcribe_cluster imports only _try_import from it, and _transcribe_diarize imports from both.",
    "transcribe_fw.py now imports get_media_duration from _transcribe_media rather than through _transcribe_diarize. This was forced by ruff removing the now-unused re-export, and is the correct outcome under the no-barrels rule - import sites should name the owning module.",
    "Test modules were re-pointed to the module that owns each function. The audio tests span two modules: _load_audio stayed put and still patches its own namespace, while the direct transcode and cleanup calls now name _transcribe_media."
  ],
  "verification": [
    {
      "command": "python3 verify_split.py HEAD .../_transcribe_diarize.py <three modules>",
      "result": "pass",
      "evidence": "IDENTICAL: all 13 top-level definitions moved verbatim. Re-run after ruff's autofixes and the import re-point, and still identical."
    },
    {
      "command": "AST scan for names used but not bound in each of the three modules",
      "result": "pass",
      "evidence": "All three report no unbound names, confirming the three module-level constants (_NDIM_2D, _SAMPLE_RATE_16K, _MIN_SAMPLES_DIAR) travelled to the modules that use them."
    },
    {
      "command": "pytest linux_configuration/tests/test_transcribe_diarize_*.py --cov of all three modules --cov-branch",
      "result": "pass",
      "evidence": "63 passed - the same count as before the split. _transcribe_cluster.py 51 statements / 18 branches, _transcribe_diarize.py 81 / 22, _transcribe_media.py 59 / 12, all 100%."
    },
    {
      "command": "python3 transcribe_fw.py /nonexistent.wav; echo $?",
      "result": "pass",
      "evidence": "Exit 2, the code transcribe.sh branches on, and --help exits 0. This is what caught a real breakage: ruff had removed the get_media_duration re-export as unused, and transcribe_fw.py imported it from there. Only running it (and the full suite) surfaced that."
    },
    {
      "command": "pytest linux_configuration/tests/ -q",
      "result": "pass",
      "evidence": "338 passed, unchanged from before the split."
    },
    {
      "command": "pre-commit run --files <changed files>",
      "result": "pass",
      "evidence": "All hooks pass. The shebang-executable hook reads the git index rather than the filesystem, so the new modules' mode change had to be staged with git add --chmod=+x before it would pass."
    },
    {
      "command": "bash ~/utils/scripts/check_file_length.sh --all",
      "result": "pass",
      "evidence": "32 files over cap, down from 33. The three modules are 164, 143 and 105 lines. No Python file in the repo is now over the cap."
    }
  ],
  "risks": [
    "A three-way split adds two import edges between sibling modules resolved by bare name on sys.path[0]. That is the existing convention in this directory and the real run confirms it resolves.",
    "The get_media_duration re-export is gone, so any out-of-tree caller importing it from _transcribe_diarize would break. Only transcribe_fw.py imported it, and it was updated in the same commit."
  ],
  "rollback": [
    "git revert the commit; _transcribe_diarize.py returns to its 356-line form and the two new modules disappear.",
    "After rollback, confirm python3 transcribe_fw.py /nonexistent.wav still returns 2 and pytest linux_configuration/tests/ reports 338 passed."
  ]
}