feat: add slm model schemas, please run migration on prod db

Feat: add complete combined sound report creation tool (wizard), add new slm schema for each model

feat: update project header link for combined report wizard

feat: add migration script to backfill device_model in monitoring_sessions

feat: implement combined report preview template with spreadsheet functionality

feat: create combined report wizard template for report generation.

backend/models.py

@@ -257,6 +257,10 @@ class MonitoringSession(Base):
     location_id = Column(String, nullable=False, index=True)  # FK to MonitoringLocation.id
     unit_id = Column(String, nullable=True, index=True)  # FK to RosterUnit.id (nullable for offline uploads)
 
+    # Physical device model that produced this session's data (e.g. "NL-43", "NL-53", "NL-32").
+    # Null for older records; report code falls back to file-content detection when null.
+    device_model = Column(String, nullable=True)
+
     session_type = Column(String, nullable=False)  # sound | vibration
     started_at = Column(DateTime, nullable=False)
     stopped_at = Column(DateTime, nullable=True)