feat(06-02): wire CorrelationIDMiddleware + config fields + promote 5 test stubs
- backend/config.py: add log_level: str = "INFO" and log_json: bool = False
fields under Observability (Phase 6 — D-01) comment; pydantic-settings reads
LOG_LEVEL / LOG_JSON env vars automatically
- backend/main.py: add imports (uuid, time, structlog, ASGIApp/Receive/Scope/Send,
setup_logging); add CorrelationIDMiddleware raw-ASGI class (NOT BaseHTTPMiddleware
— avoids streaming buffering); call setup_logging() as first lifespan statement;
register CorrelationIDMiddleware LAST so it runs FIRST (Starlette reverse order)
- backend/tests/test_logging.py: remove all 5 xfail decorators; replace single-line
bodies with real assertions for JSON renderer, contextvar binding, X-Correlation-ID
header, no-bleed between requests, uvicorn.access propagate=False
curo1305
abe8f8ee90