chore: save session state – feature/phase-1 ready to implement

- Update session-context.md with exact resume point for next session
- Update settings.local.json with broader git permissions
- feature/grundstruktur merged to develop
- PAT authentication configured

Version: 0.2.3

backend/app/models/tenant.py

@@ -0,0 +1,40 @@
+import uuid
+from datetime import datetime, timezone
+
+from sqlalchemy import DateTime, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+
+
+class Tenant(Base):
+    __tablename__ = "tenants"
+
+    id: Mapped[uuid.UUID] = mapped_column(
+        primary_key=True, default=uuid.uuid4, index=True
+    )
+    name: Mapped[str] = mapped_column(String(255), nullable=False)
+    slug: Mapped[str] = mapped_column(String(100), unique=True, nullable=False, index=True)
+
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        nullable=False,
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        onupdate=lambda: datetime.now(timezone.utc),
+        nullable=False,
+    )
+
+    # Relationships
+    user_tenants: Mapped[list["UserTenant"]] = relationship(  # noqa: F821
+        "UserTenant", back_populates="tenant", cascade="all, delete-orphan"
+    )
+    beds: Mapped[list["Bed"]] = relationship(  # noqa: F821
+        "Bed", back_populates="tenant", cascade="all, delete-orphan"
+    )
+    plants: Mapped[list["Plant"]] = relationship(  # noqa: F821
+        "Plant", back_populates="tenant"
+    )