[itsmontoya]

Summary

Upgrade the audio decoding and resampling dependency stack:

• audioadapter to 4.0.0
• audioadapter-buffers to 4.0.0
• rubato to 3.0.0
• symphonia to 0.6.0

Migrate decoding, probing, packet handling, and audio-buffer conversion to the new Symphonia APIs.

Behavior changes

No intentional user-facing behavior changes. Audio decoding, downmixing, resampling, and streaming transcription behavior remain unchanged.

Edge cases

• Missing audio codec parameters now produce an explicit error.
• End-of-stream handling uses Symphonia 0.6’s optional packet result.
• Recoverable decode and I/O errors continue to skip the affected packet.
• Track selection still requires a known audio codec and sample rate.

Verification

• cargo fmt --all -- --check
• cargo clippy --all-targets --features bin-scribble-cli,bin-model-downloader,bin-scribble-server -- -D warnings
• cargo check --features bin-scribble-cli,bin-model-downloader,bin-scribble-server
• ./scripts/test-all.sh

All 55 tests and doc tests pass.

Follow-up

Rubato 3 depends on audioadapter 3 internally, so both audioadapter 3 and 4 are currently present in the dependency graph. A future Rubato upgrade can remove this duplication once it supports audioadapter 4.