feat: implement Redis caching for analytics endpoints with fallback to database

tests/api/v1/conftest.py

@@ -8,10 +8,11 @@ import pytest_asyncio
 from httpx import ASGITransport, AsyncClient
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 
-from app.api.deps import get_db_session
+from app.api.deps import get_cache_backend, get_db_session
 from app.core.security import password_hasher
 from app.main import create_app
 from app.models import Base
+from tests.utils.fake_redis import InMemoryRedis
 
 
 @pytest.fixture(autouse=True)
@@ -41,6 +42,7 @@ async def session_factory() -> AsyncGenerator[async_sessionmaker[AsyncSession],
 @pytest_asyncio.fixture()
 async def client(
     session_factory: async_sessionmaker[AsyncSession],
+    cache_stub: InMemoryRedis,
 ) -> AsyncGenerator[AsyncClient, None]:
     app = create_app()
 
@@ -54,6 +56,12 @@ async def client(
                 raise
 
     app.dependency_overrides[get_db_session] = _get_session_override
+    app.dependency_overrides[get_cache_backend] = lambda: cache_stub
     transport = ASGITransport(app=app)
     async with AsyncClient(transport=transport, base_url="http://testserver") as test_client:
         yield test_client
+
+
+@pytest.fixture()
+def cache_stub() -> InMemoryRedis:
+    return InMemoryRedis()