Chunk size was hardcoded at 2.5-min bodies. Add a Settings control:
Auto / Standard 2.5min / Large group 60s / Fine 90s. Shorter chunks keep fewer
simultaneous speakers per window (Sortformer resolves ~4/chunk), useful for large
calls, at some cost to speed and cross-chunk voice matching.
- ChunkMode (new, pure/testable): mode → body seconds; Auto picks 60s when >4
participants were detected, else 150s; overlap + single-chunk threshold scale
with the body length.
- AppSettings.chunkMode (+ typed `chunk`); SettingsView picker with explanation.
- TranscriptPipeline.process gains chunkSeconds; derives overlap/threshold from it.
- SessionController resolves the body from the setting + the session's detected
participant count (visual_timeline participants) for both send + re-process.
- Participant roster now counts EVERY tile OCR'd, not just who spoke
(TimelineBuilder.observedNames → VisualObserver → VisualCapture), so the Auto
call-size signal is meaningful even though speaking-detection is sparse.
Tests: ChunkMode resolution, overlap scaling, short-body re-chunking. 69 pass.
Grant Gilliam