Auto/Manual/Off tail handling for realtime track-tap capture. Auto scans
recorded PCM backward for last frame above -72 dB and truncates the wav
header-aware (8 s cap); Manual pads a fixed tail; Off is byte-identical.
wav_trim rejects WAVE_FORMAT_EXTENSIBLE with non-float SubFormat GUID.
Docked SWELL window toggled by a new action, drawing the current bank as
per-sample min/max thumbnails (PCM_source + peaks) with an in-memory cache.
Pure grid-layout/cache-key math in bank_grid (tested). Renames peaks::Sample
-> AudioSample to avoid colliding with bank_model::Sample.
New STATIC lib + peaks_tests (CTest), mirroring bank_model. Float samples,
per-channel (no fold); exact integer bin spans handle remainder, short
buffers, and degenerate inputs with no OOB. Bin-span math guarded against
size_t overflow for pathological binCount.
daniel