v0.2 fleet overhaul

backend/models.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Column, String, DateTime, Boolean, Text
+from sqlalchemy import Column, String, DateTime, Boolean, Text, Date
 from datetime import datetime
 from backend.database import Base
 
@@ -18,11 +18,15 @@ class RosterUnit(Base):
     """
     Roster table: represents our *intended assignment* of a unit.
     This is editable from the GUI.
+
+    Supports multiple device types (seismograph, modem) with type-specific fields.
     """
     __tablename__ = "roster"
 
+    # Core fields (all device types)
     id = Column(String, primary_key=True, index=True)
-    unit_type = Column(String, default="series3")
+    unit_type = Column(String, default="series3")  # Backward compatibility
+    device_type = Column(String, default="seismograph")  # "seismograph" | "modem"
     deployed = Column(Boolean, default=True)
     retired = Column(Boolean, default=False)
     note = Column(String, nullable=True)
@@ -30,6 +34,16 @@ class RosterUnit(Base):
     location = Column(String, nullable=True)
     last_updated = Column(DateTime, default=datetime.utcnow)
 
+    # Seismograph-specific fields (nullable for modems)
+    last_calibrated = Column(Date, nullable=True)
+    next_calibration_due = Column(Date, nullable=True)
+    deployed_with_modem_id = Column(String, nullable=True)  # FK to another RosterUnit
+
+    # Modem-specific fields (nullable for seismographs)
+    ip_address = Column(String, nullable=True)
+    phone_number = Column(String, nullable=True)
+    hardware_model = Column(String, nullable=True)
+
 
 class IgnoredUnit(Base):
     """