M0: implement operational core

Backend: SQLAlchemy models, Alembic migrations, requirements lockfile. Frontend: pinned deps, package-lock, vite-env types fix. Verified compose build/health, pytest, ruff clean.

backend/app/models/booking.py

@@ -0,0 +1,29 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, Integer, String
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.core.db import Base
+from app.models.mixins import TimestampMixin, UUIDPrimaryKeyMixin
+
+BOOKING_STATUSES = ("reserved", "active", "returned", "cancelled", "blocked")
+
+
+class Booking(UUIDPrimaryKeyMixin, TimestampMixin, Base):
+    __tablename__ = "bookings"
+
+    public_ref: Mapped[str] = mapped_column(String(20), unique=True, nullable=False)
+    customer_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("customers.id"), nullable=False
+    )
+    vehicle_id: Mapped[uuid.UUID] = mapped_column(
+        UUID(as_uuid=True), ForeignKey("vehicles.id"), nullable=False
+    )
+    starts_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    ends_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
+    status: Mapped[str] = mapped_column(String(20), nullable=False)
+    start_odometer_km: Mapped[int | None] = mapped_column(Integer)
+    end_odometer_km: Mapped[int | None] = mapped_column(Integer)
+    requirements_complete: Mapped[bool] = mapped_column(Boolean, nullable=False, default=True)