- file_ops.probe_audio_quality: .aiff/.aif were opened with mutagen.wave.WAVE,
which can't parse AIFF — it raised, failed open, and let AIFF silently bypass
the quality filter. Route aiff/aif to mutagen.aiff.AIFF (still the 'wav'
lossless tier).
- test_hifi_preview_guard: _get_hls_manifest gained an expected_duration_s kwarg
and the start tier now comes from quality_tier_for_source (default profile ->
'hires'); accept the kwarg and pin the tier so the chain is deterministic.
- test_quarantine_management: quarantine_group_key intentionally no longer uses
source-specific ids/uri (they break cross-batch sibling matching); assert the
isrc -> normalized-name contract instead.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>