feat: delete a track

everything should be ready and safe for it to delete logically a track for a session (not the associated file yet)

No specific files or tests are listed. Start by finding the TypeScript code path that deletes tracks for a session (API handler/service and data model), then inspect related session-track and storage code to separate logical record deletion from file removal. Run whatever track/session tests exist in that area to confirm current behavior. Done means the track is logically deleted for a session while associated file handling is unchanged.

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