fix(e2e): resolve async fixture and API availability issues

- Use @pytest_asyncio.fixture for proper async fixture handling
- Change pg_engine scope to function to avoid event loop conflicts
- Load .env via dotenv for local DATABASE_URL discovery
- Remove custom event_loop fixture (pytest-asyncio handles it)
- Patch is_db_configured() to fix 503 Service Unavailable responses

All 484 tests pass (465 unit/integration + 19 E2E).

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: MarkusNeusinger

tests/e2e/conftest.py

@@ -8,6 +8,7 @@
 import os
 
 import pytest
+import pytest_asyncio
 from sqlalchemy import text
 from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine
 
@@ -21,26 +22,22 @@
 TEST_THUMB_URL = "https://storage.googleapis.com/pyplots-images/test/thumb.png"
 
 
-@pytest.fixture(scope="session")
-def event_loop():
-    """Create event loop for session-scoped async fixtures."""
-    import asyncio
+def _get_database_url():
+    """Get DATABASE_URL from environment, loading .env if needed."""
+    from dotenv import load_dotenv
+    load_dotenv()
+    return os.environ.get("DATABASE_URL")
 
-    policy = asyncio.get_event_loop_policy()
-    loop = policy.new_event_loop()
-    yield loop
-    loop.close()
 
-
-@pytest.fixture(scope="session")
+@pytest_asyncio.fixture(scope="function")
 async def pg_engine():
     """
     Create PostgreSQL engine and setup test schema.
 
     Creates a separate 'test_e2e' schema to isolate tests from production data.
-    The schema is dropped and recreated at the start of the test session.
+    The schema is dropped and recreated for each test.
     """
-    database_url = os.environ.get("DATABASE_URL")
+    database_url = _get_database_url()
     if not database_url:
         pytest.skip("DATABASE_URL not set - skipping PostgreSQL E2E tests")
 
@@ -61,7 +58,7 @@ async def pg_engine():
     await engine.dispose()
 
 
-@pytest.fixture
+@pytest_asyncio.fixture
 async def pg_session(pg_engine):
     """Create session with test schema."""
     async_session = async_sessionmaker(pg_engine, class_=AsyncSession, expire_on_commit=False)
@@ -72,7 +69,7 @@ async def pg_session(pg_engine):
         await session.rollback()
 
 
-@pytest.fixture
+@pytest_asyncio.fixture
 async def pg_db_with_data(pg_session):
     """
     Seed test schema with sample data.

tests/e2e/test_api_postgres.py

@@ -9,6 +9,8 @@
 local development without PostgreSQL.
 """
 
+from unittest.mock import patch
+
 import pytest
 from httpx import ASGITransport, AsyncClient
 
@@ -35,8 +37,12 @@ async def override_get_db():
         yield pg_db_with_data
 
     app.dependency_overrides[get_db] = override_get_db
-    async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
-        yield ac
+
+    # Patch is_db_configured to return True (it checks env vars, not dependencies)
+    with patch("api.dependencies.is_db_configured", return_value=True):
+        async with AsyncClient(transport=ASGITransport(app=app), base_url="http://test") as ac:
+            yield ac
+
     app.dependency_overrides.clear()