fix: align audio effect transition properties

[han4wluc]

Summary

• align transition effects with update effects by supporting volume, pan, and playbackRate property tracks
• compile outgoing and incoming transition tracks through the shared audio-property path
• persist incoming transition endpoints so runtime state matches the completed effect
• update the project-data schema, generated validator, tests, and audio-channel VT fixtures
• release the correction as Route Engine version 1.45.2

Contract

• outgoing and incoming transitions accept volume, pan, and playbackRate
• incoming transition endpoints become the persistent BGM values after completion, matching update-effect semantics

Testing

• bun run test — 2,055 passed
• bun run lint
• bun run format:changed

Related

• Creator model: fix: align audio effect transition properties routevn-creator-model#76