New database table: maintenance_records
- Fields: asset, start_date, end_date, status (open/in_progress/closed),
initial_diagnosis, action_taken, action_result
New routes (/maintenance/):
- List with status + asset filters and pagination
- POST /new — create record (editor+); auto-sets asset status to 'maintenance'
- GET /<id>/edit — opens list page with modal pre-filled
- POST /<id>/update — save edits; auto-clears 'maintenance' status on close
- POST /<id>/delete — remove record
UI:
- Bootstrap modal form shared for add and edit
- Clicking any table row opens the modal pre-filled with that row's data
- Asset field locked in edit mode (cannot change asset)
- Delete button per row (with confirmation)
- Sidebar: 'Maintenance' link added under Hardware section