[Xehanort88]

Summary

Trimming keeps all metadata

• WAV files are now trimmed at the chunk level: every chunk is copied verbatim (tags, smpl sampler loops, cue points, bext, the exact fmt chunk). Only the data chunk is shortened, and the fact sample count is updated. The audio is no longer rewritten. A data size left as a placeholder (0 or past the end of the file) by an interrupted writer is handled.
• FLAC audio is still re-encoded losslessly, but the source's metadata blocks are restored onto it: tags, cover art, application blocks, padding, and surrounding ID3 tags. Only the seek table and cue sheet are dropped, since they point into the old audio. If this fails, it falls back to copying text tags, with a warning.
• Ogg Vorbis streams whose granule positions start past 0 (e.g. recorded from a live stream) are now cut at the right sample. Decoders number samples from the stream's start granule.
• Failures to copy tags (used by trim and extend) are now logged as warnings instead of being silently ignored.

WAV smpl loop points

• A WAV file with no loop tags has its first forward smpl loop used as the embedded loop: it is the first choice for all commands, and is used by play-tagged when no tag names are given. Text tags take precedence, and explicitly named tags never fall back to smpl.
• tag on WAV files also writes the loop to the smpl chunk (as a forward loop with an inclusive end, repeating forever). An existing chunk keeps its header, its other loops and its sampler-specific data.
• WAV chunks are found by reading only their headers, so looking for a smpl loop doesn't load the whole file.

Other fixes

• The interactive trim prompt is no longer shown when export-points only prints to the console.
• Detected loops within 5 ms of the embedded loop points are left out, so the same loop isn't listed twice.
• trim --keep-after now defaults to 100 samples, the same as the interactive prompt (one shared constant). The Python API's MusicLooper.trim() still defaults to 0.

Behaviour change

Running trim without --keep-after now keeps 100 samples after the loop end instead of 0. Pass --keep-after 0 to cut exactly at the loop end.

Testing

• 129 tests pass locally. The 2 FFmpeg decoder tests were skipped because FFmpeg wasn't installed.
• The Tests workflow passed on both commits (Ubuntu and Windows, Python 3.10 and 3.13).
• End to end, trim and tag were run on WAV files that have tags and a smpl chunk.