All 13 environment variables from the spec defined with proper defaults.
SQLite fallback when DATABASE_URL is unset, in-process queue flag when
REDIS_URL is unset, JWT_SECRET auto-generation, empty API_KEY normalization.
13 unit tests covering all configuration paths.
Set up all directories from the spec's Project Structure section:
- backend/ with routers/, engine/adapters/, engine/scorers/, mcp/,
websocket/, tests/ (all with __init__.py)
- frontend/src/ with pages/, components/, api/ (.gitkeep)
- docker/ (.gitkeep)
- alembic/versions/ (.gitkeep)
