- Replace all UnitAssignment "active" checks from `status == "active"` to
`assigned_until == None` in both project_locations.py and projects.py.
This aligns with the canonical definition: active = no end date set.
(status field is still set in sync, but is no longer the query criterion)
- Add `_require_sound_project()` helper to both routers and call it at the
top of every sound-monitoring-specific endpoint (FTP browser, FTP downloads,
RND file viewer, all Excel report endpoints, combined report wizard,
upload-all, NRL live status, NRL data upload). Vibration projects hitting
these endpoints now receive a clear 400 instead of silently failing or
returning empty results.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>