Move shared type contracts from `contracts` to new `api-contracts` module in `compute/core` for clearer API boundaries. Remove legacy `contracts`, `pdf`, and `whisper` index files. Update all imports to use `api-contracts`. Refactor server job logic by replacing `parsePdfJob.ts` with modular `user-pdf-layout-job.ts` and `user-whisper-align-job.ts`, updating all relevant API routes and compute integration. This improves maintainability and separation of concerns across compute and server layers.
