fix(player): create animated AVIF scenes from MediaCodec output

[bee-san]

Problem

Jellyfin scene mining fell back to a still because the bundled FFmpeg MediaCodec encoder wrapper prepended MediaCodec’s AV1CodecConfigurationRecord to the next AV1 packet. FFmpeg’s downstream parser then correctly rejected the non-OBU record header.

Fix: remove av1C (among fixing other bugs)

Summary

• allow 10-bit SDR scene input while continuing to reject HDR
• normalize MediaCodec AV1 packets before remuxing them into animated AVIF
• keep encode/remux cancellable and defer resource cleanup until native FFmpeg returns

Testing

• ./gradlew assemblePreview --no-daemon
• 38 focused scene unit tests, including cancellation and deferred-cleanup coverage
• Spotless single-file checks for all changed files
• manually verified animated AVIF creation on a Galaxy S24 Ultra with Pokemon Concierge through Jellyfin

The hosted spotlessCheck failure reproduces on clean upstream/main in unchanged presentation-core and domain files. The full unit-test task is also blocked on clean upstream/main because ReaderOcrSourceTest omits its required mokuroAvailable argument. Neither baseline issue is included here, keeping this PR focused.

Prepared with assistance from OpenAI Codex.