fix(audio): P1-P3 fixes from audio code reviewHEADmain

P1 — correctness bugs:
- tracker.cc: move delete[] loop before pool reset so guard condition is valid
- audio_engine: replace tracker_reset() with tracker_init() in reset()/seek()
  so synth IDs are re-registered after synth_init() clears spectrogram slots
- spectrogram_resource_manager: set spec.version in load_procedural() (was UB)

P2 — minor bugs:
- synth.cc: move pan clamp unconditionally before debug-only block
- gen.cc: remove dead `freq` variable in generate_note_spectrogram()
- tracker.cc: remove duplicate g_sample_synth_cache clear loop

P3 — cleanup:
- Replace hardcoded 32000.0f with RING_BUFFER_SAMPLE_RATE (5 sites)
- audio.cc: extract clip_samples() helper, remove duplicated clip loops
- audio_engine: inline update_silent(), remove no-op prewarm_for_time_range()
- Remove stale comments: stdio.h include, NEW: labels, CACHING block, NOTE:
- Move TODO(timing) drift notes from source to TODO.md

handoff(Gemini): audio review implemented, 36/36 tests passing

0 files changed, 0 insertions, 0 deletions