Add schedule and unit list templates for project management

- Created `schedule_list.html` to display scheduled actions with execution status, location, and timestamps.
- Implemented buttons for executing and canceling schedules, along with a details view placeholder.
- Created `unit_list.html` to show assigned units with their status, location, model, and session/file counts.
- Added conditional rendering for active sessions and links to view unit and location details.

backend/main.py

@@ -233,8 +233,11 @@ async def nrl_detail_page(
     # Get session count
     session_count = db.query(RecordingSession).filter_by(location_id=location_id).count()
 
-    # Get file count
-    file_count = db.query(DataFile).filter_by(location_id=location_id).count()
+    # Get file count (DataFile links to session, not directly to location)
+    file_count = db.query(DataFile).join(
+        RecordingSession,
+        DataFile.session_id == RecordingSession.id
+    ).filter(RecordingSession.location_id == location_id).count()
 
     # Check for active session
     active_session = db.query(RecordingSession).filter(