feat: T03 backend core – FastAPI + DB models + Equipment API + Redis cache + health + tests

- FastAPI app with CORS, lifespan handlers
- Pydantic Settings config (DB, Redis, CORS, SMTP, JWT, Rentman)
- SQLAlchemy async engine + session (DeclarativeBase)
- 6 DB models: EquipmentCache, RentalRequest, RentalRequestItem, Contact, AdminUser, SyncLog
- Pydantic schemas: EquipmentItem, EquipmentDetail, PaginatedEquipment, ContactCreate, ContactResponse
- Redis cache helper: set/get/delete_pattern, rate limiting, equipment key builders
- Equipment router: list (search/category/sort/pagination), detail, categories – all cached
- Contact router: POST with Pydantic validation + rate limiting (5/min)
- Health router: GET /api/health with DB + Redis status
- 28 pytest tests (all pass, 90% coverage)
- Dockerfile, requirements.txt, pytest.ini, test_report.md

backend/tests/test_models.py

@@ -0,0 +1,98 @@
+"""Tests for SQLAlchemy model definitions and table creation."""
+
+from datetime import date
+
+import pytest
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from app.models.admin_user import AdminUser
+from app.models.contact import Contact
+from app.models.equipment import EquipmentCache
+from app.models.rental_request import RentalRequest, RentalRequestItem
+from app.models.sync_log import SyncLog
+
+
+@pytest.mark.asyncio
+async def test_equipment_cache_model(db_session: AsyncSession):
+    """EquipmentCache model can be instantiated and queried."""
+    item = EquipmentCache(
+        rentman_id="999", name="Test Speaker", number="TS-001",
+        category="Lautsprecher", description="Test item",
+    )
+    db_session.add(item)
+    await db_session.commit()
+    await db_session.refresh(item)
+    assert item.id is not None
+    assert item.rentman_id == "999"
+    assert item.available is True
+
+
+@pytest.mark.asyncio
+async def test_rental_request_model(db_session: AsyncSession):
+    """RentalRequest and RentalRequestItem models work with relationships."""
+    req = RentalRequest(
+        reference_number="HMS-2026-00001",
+        event_name="Test Event",
+        date_start=date(2026, 8, 15),
+        date_end=date(2026, 8, 16),
+        contact_name="Max Mustermann",
+        contact_email="max@example.com",
+    )
+    db_session.add(req)
+    await db_session.commit()
+    await db_session.refresh(req)
+
+    item = RentalRequestItem(
+        rental_request_id=req.id,
+        equipment_name="Test Speaker",
+        quantity=2,
+    )
+    db_session.add(item)
+    await db_session.commit()
+
+    # Use explicit query with selectinload to avoid lazy loading in async
+    result = await db_session.execute(
+        select(RentalRequest).options(selectinload(RentalRequest.items)).where(RentalRequest.id == req.id)
+    )
+    loaded_req = result.scalar_one()
+    assert len(loaded_req.items) == 1
+    assert loaded_req.items[0].quantity == 2
+
+
+@pytest.mark.asyncio
+async def test_contact_model(db_session: AsyncSession):
+    """Contact model can store a contact form submission."""
+    contact = Contact(
+        name="Max", email="max@example.com", message="Hello",
+        privacy_consent=True,
+    )
+    db_session.add(contact)
+    await db_session.commit()
+    await db_session.refresh(contact)
+    assert contact.id is not None
+    assert contact.email_sent is False
+
+
+@pytest.mark.asyncio
+async def test_admin_user_model(db_session: AsyncSession):
+    """AdminUser model stores username and password hash."""
+    user = AdminUser(username="admin", password_hash="hashed_secret")
+    db_session.add(user)
+    await db_session.commit()
+    await db_session.refresh(user)
+    assert user.id is not None
+    assert user.username == "admin"
+
+
+@pytest.mark.asyncio
+async def test_sync_log_model(db_session: AsyncSession):
+    """SyncLog model stores sync metadata."""
+    log = SyncLog(sync_type="equipment", status="running")
+    db_session.add(log)
+    await db_session.commit()
+    await db_session.refresh(log)
+    assert log.id is not None
+    assert log.status == "running"
+    assert log.items_processed == 0