`b5c6d9ac0` ("fix: wire STT lazy-install into transcription_tools.py")
added `_try_lazy_install_stt()`, which calls
`importlib.util.find_spec("faster_whisper")` after `ensure()` runs.
In the dev / CI environment `faster_whisper` is already installed, so
the probe returns truthy and `_get_provider()` returns "local" even
when the test has patched `_HAS_FASTER_WHISPER=False` to simulate
"not installed".
Add a per-file autouse fixture that patches `_try_lazy_install_stt`
to return False so the simulation stays accurate. The 16 baseline
failures across `test_transcription_tools.py`,
`test_transcription.py`, and `test_transcription_dotenv_fallback.py`
disappear; the production lazy-install path is unaffected at runtime.
5dc232a6e2