[Zer0codestuff]

What changes

• A note's folders in Audio and Transcripts, and its recording, carry the note's title instead of an identifier: Audio/Lesson 1/Lesson 1.m4a. A note with both sources gets Lesson 1 - You.m4a and Lesson 1 - Others.m4a. Renaming a note renames them. A second note with the same title gets Lesson 1 2.
• Kept audio is AAC in an M4A file at 48 kbit/s, about 22 MB per hour instead of 115 MB of PCM in a CAF.
• Recording still writes PCM to a CAF, so a crash keeps the audio. The CAF is converted when the note ends and removed only after the M4A reports the same number of frames.
• On launch, notes from earlier versions are named, and their CAF recordings are converted in the background. Each original goes to the Trash after the same check.
• Job URLs and the rename list are committed together in history.json before anything moves. Relaunch finishes an interrupted rename, and a failed rename is put back.
• Scripts and CI pass --build-system native. The default build system in Xcode 27 compiles the mlx-swift Metal sources and fails without the Metal Toolchain component.

Checks

• 154 standard tests pass in debug and release, ten optional skips.
• Silent session replay of a 4-minute excerpt at recording speed: no dropped packets, PCM sample-identical to the input, M4A holds all 3,840,000 frames.
• Dry run of the launch conversion on a copy of a real library: seven notes named, six recordings converted, 1,020.5 MB to 191.3 MB in 17.3 s on an M4, frame counts equal, transcripts unchanged.
• The built app was launched on an isolated synthetic library in the old layout and named and converted it.
• Bit rate: Parakeet v3 made the same 7 errors on a 347-word synthetic reference from PCM, 32 and 48 kbit/s. On the quiet version, 32 kbit/s made 9 errors and 48 made 7. Details and limits are in docs/audio-storage-and-cleanup.md.

Not done

• Renaming a note through the UI of the built app was not tried. The store path is covered by tests.
• No version bump and no release.