fix(tests): isolate SQLite test databases

Co-authored-by: OpenAI/GPT-5.6-Terra <vibecoder@antoineve.me>

tests/test_app_factory.py

@@ -0,0 +1,11 @@
+import sqlalchemy as sa
+from sqlalchemy.pool import StaticPool
+
+from app import db
+
+
+def test_app_fixture_uses_one_in_memory_database_connection(app):
+    with app.app_context():
+        assert str(db.engine.url) == "sqlite:///:memory:"
+        assert isinstance(db.engine.pool, StaticPool)
+        assert sa.inspect(db.engine).has_table("work_entries")