Add silence-trim subcommand (alias st): collapse long pauses, v7-hardened
- sermon_clean/silence_trim.py: function-form silence_trim(audio, output, ...) -> SilenceTrimResult
with full v7 guards (silencedetect nonzero-exit raise, min>keep validation, full-N
lossless WAV complexity trial, >5% drift abort)
- sermon_clean/cli.py: cmd_silence_trim() + p_st parser registered before p_pipe
- Verified end-to-end on synthetic 20-cycle 9.00s WAV (drift 0.13%, complexity trial ran)
- Invalid-range rejections verified: min<=keep, min<=0, test_segments<=0 → rc=1
- Source: closed prior-tick pickup from _drafts/audio-silence-trim/ SKILL.md
sami7777
612c184317