feat: add multi-tenant system with properties, organizations, and public booking

Implement complete multi-property architecture:
- Properties (groups of spaces) with public/private visibility
- Property managers (many-to-many) with role-based permissions
- Organizations with member management
- Anonymous/guest booking support via public API (/api/public/*)
- Property-scoped spaces, bookings, and settings
- Frontend: property selector, organization management, public booking views
- Migration script and updated seed data

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/seed_db.py

@@ -1,12 +1,18 @@
-"""Seed database with initial data."""
+"""Seed database with initial data for multi-property system."""
 from app.core.security import get_password_hash
 from app.db.session import Base, SessionLocal, engine
+from app.models.organization import Organization
+from app.models.organization_member import OrganizationMember
+from app.models.property import Property
+from app.models.property_access import PropertyAccess
+from app.models.property_manager import PropertyManager
 from app.models.settings import Settings
+from app.models.space import Space
 from app.models.user import User
 
 
 def seed_database() -> None:
-    """Create initial users for testing."""
+    """Create initial data for testing multi-property system."""
     # Create tables
     Base.metadata.create_all(bind=engine)
 
@@ -18,16 +24,27 @@ def seed_database() -> None:
             print("Database already seeded. Skipping...")
             return
 
-        # Create admin user
-        admin = User(
+        # Create superadmin user
+        superadmin = User(
             email="admin@example.com",
-            full_name="Admin User",
+            full_name="Super Admin",
             hashed_password=get_password_hash("adminpassword"),
-            role="admin",
+            role="superadmin",
             organization="Management",
             is_active=True,
         )
-        db.add(admin)
+        db.add(superadmin)
+
+        # Create manager user
+        manager = User(
+            email="manager@example.com",
+            full_name="Property Manager",
+            hashed_password=get_password_hash("managerpassword"),
+            role="manager",
+            organization="Management",
+            is_active=True,
+        )
+        db.add(manager)
 
         # Create regular user
         user = User(
@@ -40,6 +57,93 @@ def seed_database() -> None:
         )
         db.add(user)
 
+        db.flush()  # Get IDs
+
+        # Create properties
+        prop1 = Property(
+            name="Clădirea Centrală",
+            description="Clădirea principală din centru",
+            address="Str. Principală nr. 1",
+            is_public=True,
+            is_active=True,
+        )
+        db.add(prop1)
+
+        prop2 = Property(
+            name="Biroul Privat",
+            description="Spațiu privat pentru echipă",
+            address="Str. Secundară nr. 5",
+            is_public=False,
+            is_active=True,
+        )
+        db.add(prop2)
+
+        db.flush()  # Get property IDs
+
+        # Assign manager to both properties
+        db.add(PropertyManager(property_id=prop1.id, user_id=manager.id))
+        db.add(PropertyManager(property_id=prop2.id, user_id=manager.id))
+
+        # Create spaces (2 in first property, 1 in second)
+        space1 = Space(
+            name="Sala Mare",
+            type="sala",
+            capacity=20,
+            description="Sală de conferințe mare",
+            is_active=True,
+            property_id=prop1.id,
+        )
+        db.add(space1)
+
+        space2 = Space(
+            name="Birou A1",
+            type="birou",
+            capacity=4,
+            description="Birou deschis",
+            is_active=True,
+            property_id=prop1.id,
+        )
+        db.add(space2)
+
+        space3 = Space(
+            name="Sala Privată",
+            type="sala",
+            capacity=10,
+            description="Sală privată pentru echipă",
+            is_active=True,
+            property_id=prop2.id,
+        )
+        db.add(space3)
+
+        # Create organizations
+        org1 = Organization(
+            name="Engineering",
+            description="Echipa de dezvoltare",
+            is_active=True,
+        )
+        db.add(org1)
+
+        org2 = Organization(
+            name="Management",
+            description="Echipa de management",
+            is_active=True,
+        )
+        db.add(org2)
+
+        db.flush()  # Get org IDs
+
+        # Create organization members
+        db.add(OrganizationMember(organization_id=org1.id, user_id=user.id, role="member"))
+        db.add(OrganizationMember(organization_id=org2.id, user_id=manager.id, role="admin"))
+        db.add(OrganizationMember(organization_id=org2.id, user_id=superadmin.id, role="admin"))
+
+        # Grant user access to private property
+        db.add(PropertyAccess(
+            property_id=prop2.id,
+            user_id=user.id,
+            granted_by=manager.id,
+        ))
+
         # Create default settings if not exist
         existing_settings = db.query(Settings).filter(Settings.id == 1).first()
         if not existing_settings:
@@ -55,9 +159,12 @@ def seed_database() -> None:
             db.add(default_settings)
 
         db.commit()
-        print("✓ Database seeded successfully!")
-        print("Admin: admin@example.com / adminpassword")
+        print("Database seeded successfully!")
+        print("Superadmin: admin@example.com / adminpassword")
+        print("Manager: manager@example.com / managerpassword")
         print("User: user@example.com / userpassword")
+        print(f"Properties: '{prop1.name}' (public), '{prop2.name}' (private)")
+        print(f"Organizations: '{org1.name}', '{org2.name}'")
     except Exception as e:
         print(f"Error seeding database: {e}")
         db.rollback()