Logging: full AppHandle Debug dump on every line of transcribe_audio (≈96% of log size) #2367

Description

The transcribe_audio span includes app: AppHandle without skip, so every event inside it
prints the full AppHandle Debug output (~9 KB: Tauri config, CSP, plugin list, state TypeIds...).
Combined with per-chunk INFO logging during resampling (Processing chunk N /
Successfully resampled chunk N, 818 lines for one 14-min file), a single transcription attempt
produced a 7.7 MB log: 950 lines, 837 of them with the dump. Without the dumps it's 322 KB.

Suggested:

• #[instrument(skip(app))] on transcribe_audio (and any other command taking AppHandle).
• Per-chunk progress at DEBUG/TRACE, or one progress line per N%.
• Minor: daily log files are named cap-desktop.log.2026-09-28; macOS doesn't treat them as
  logs (no Console.app double-click). RollingFileAppender::builder().filename_suffix("log")
  would give cap-desktop.2026-09-28.log.
• Minor: System audio dropping frames WARN is repeated every 5 s even when the drop counter
  hasn't changed.

Additional Context

• Cap version: 0.6.0
• Operating system, version: 26.2 (25C56)
• Device (optional): Macbook M1

cap-desktop-2.log