Overflights implementation

backend/app/models/overflight.py

@@ -0,0 +1,28 @@
+from sqlalchemy import Column, Integer, String, DateTime, Text, Enum as SQLEnum, BigInteger
+from sqlalchemy.sql import func
+from enum import Enum
+from app.db.session import Base
+
+
+class OverflightStatus(str, Enum):
+    ACTIVE = "ACTIVE"
+    INACTIVE = "INACTIVE"
+    CANCELLED = "CANCELLED"
+
+
+class Overflight(Base):
+    __tablename__ = "overflights"
+    
+    id = Column(BigInteger, primary_key=True, autoincrement=True)
+    registration = Column(String(16), nullable=False, index=True)
+    pob = Column(Integer, nullable=True)  # Persons on board
+    type = Column(String(32), nullable=True)  # Aircraft type
+    departure_airfield = Column(String(64), nullable=True, index=True)  # Airfield they departed from
+    destination_airfield = Column(String(64), nullable=True, index=True)  # Where they're heading
+    status = Column(SQLEnum(OverflightStatus), nullable=False, default=OverflightStatus.ACTIVE, index=True)
+    call_dt = Column(DateTime, nullable=False, index=True)  # Time of initial call
+    qsy_dt = Column(DateTime, nullable=True)  # Time of frequency change (QSY)
+    notes = Column(Text, nullable=True)
+    created_dt = Column(DateTime, nullable=False, server_default=func.current_timestamp(), index=True)
+    created_by = Column(String(16), nullable=True, index=True)
+    updated_at = Column(DateTime, nullable=False, server_default=func.current_timestamp(), onupdate=func.current_timestamp())