feat: Quart app factory with health endpoint

tests/test_app.py

@@ -0,0 +1,21 @@
+import pytest
+from fablednetmon.app import create_app
+
+
+@pytest.mark.asyncio
+async def test_create_app_returns_quart_app(config_file):
+    from quart import Quart
+    app = create_app(config_path=config_file, testing=True)
+    assert isinstance(app, Quart)
+
+
+@pytest.mark.asyncio
+async def test_app_has_db_sessionmaker(config_file):
+    app = create_app(config_path=config_file, testing=True)
+    assert hasattr(app, "db_sessionmaker")
+
+
+@pytest.mark.asyncio
+async def test_health_endpoint(client):
+    response = await client.get("/health")
+    assert response.status_code == 200