Switch tts_segments schema to use settings_json (jsonb for Postgres, text for SQLite)
instead of settings_hash. Update related indexes and migration SQL. Regenerate
Drizzle snapshots to reflect the new structure. This improves flexibility for
storing TTS settings and enables more robust segment lookups.
Introduce TTS segment support with new database tables and migrations for both Postgres and SQLite. Implement segment ensure, audio, and manifest API endpoints, segment storage in S3, and segment authorization logic. Update TTS context and client API to use segment-based synthesis and retrieval. Add server-side helpers for segment ID, settings hash, locator normalization, and audio probing. Extend user data cleanup and teardown logic to remove TTS segment objects. Add unit tests for segment helpers.
BREAKING CHANGE: TTS synthesis now uses segment-based storage and APIs; database migrations required.
