Replace the previous whisper.cpp-based word alignment with a fully ONNX-based
implementation using onnxruntime-node and @huggingface/tokenizers. Add new
Whisper ONNX model management, alignment mapping, and spectral analysis modules.
Remove all code and documentation referencing whisper.cpp, update environment
variables, Dockerfile, and docs to reflect ONNX-only alignment. Add unit tests
for alignment and ONNX model logic.
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.
