Fix deletion of records and subjects with uploaded files

[MiroslavGit]

Closes #1572.

Summary

• authorize deletion before reading dependent file metadata
• delete InstrumentRecordFile rows before deleting records in the same database transaction
• delete physical storage objects only after the database transaction commits
• log storage cleanup failures so orphaned objects can be recovered manually
• support both individual record deletion and force-deleting subjects with uploaded files
• add storage, service, API integration, and Playwright regression tests

Validation

• targeted API unit tests: 81 passed
• API test suite: 488 passed
• Playwright E2E for record file deletion: 7 passed
• manually verified with local MongoDB and RustFS:
  • deleting a record with an uploaded file returns 204
  • force-deleting a subject with uploaded files returns 200
  • related database rows are removed
  • corresponding storage objects are removed

[joshunrau]

awesome! looks great, thanks a lot!