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/conftest.py

@@ -0,0 +1,68 @@
+"""Pytest fixtures for async tests."""
+
+import asyncio
+from typing import AsyncGenerator
+
+import fakeredis.aioredis
+import pytest
+import pytest_asyncio
+from httpx import ASGITransport, AsyncClient
+from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
+
+import app.cache as cache_module
+from app.database import Base, get_db
+from app.main import app
+
+
+@pytest.fixture(scope="session")
+def event_loop():
+    """Create a single event loop for all tests."""
+    loop = asyncio.new_event_loop()
+    yield loop
+    loop.close()
+
+
+@pytest_asyncio.fixture
+async def test_engine():
+    """Create a fresh in-memory SQLite engine for each test."""
+    engine = create_async_engine("sqlite+aiosqlite:///:memory:", echo=False)
+    async with engine.begin() as conn:
+        await conn.run_sync(Base.metadata.create_all)
+    yield engine
+    await engine.dispose()
+
+
+@pytest_asyncio.fixture
+async def db_session(test_engine) -> AsyncGenerator[AsyncSession, None]:
+    """Yield a DB session bound to the test engine."""
+    session_factory = async_sessionmaker(test_engine, class_=AsyncSession, expire_on_commit=False)
+    async with session_factory() as session:
+        yield session
+
+
+@pytest_asyncio.fixture
+async def fake_redis():
+    """Provide a fakeredis instance and patch the cache module global."""
+    fake = fakeredis.aioredis.FakeRedis(decode_responses=True)
+    cache_module._cache_client = fake
+    yield fake
+    cache_module._cache_client = None
+    await fake.flushall()
+
+
+@pytest_asyncio.fixture
+async def client(test_engine, fake_redis) -> AsyncGenerator[AsyncClient, None]:
+    """Provide an async HTTP client with test DB and fake Redis."""
+    session_factory = async_sessionmaker(test_engine, class_=AsyncSession, expire_on_commit=False)
+
+    async def override_get_db() -> AsyncGenerator[AsyncSession, None]:
+        async with session_factory() as session:
+            yield session
+
+    app.dependency_overrides[get_db] = override_get_db
+
+    transport = ASGITransport(app=app)
+    async with AsyncClient(transport=transport, base_url="http://test") as ac:
+        yield ac
+
+    app.dependency_overrides.clear()