refactor: address python review findings

- Move FRED credential registration to FastAPI lifespan (was fragile
  import-order-dependent side-effect)
- Add noqa E402 annotations for imports after curl_cffi patch
- Fix all return type hints: bare dict -> dict[str, Any]
- Move yfinance import to module level (was inline in functions)
- Fix datetime.now() -> datetime.now(tz=timezone.utc) in openbb_service
- Add try/except error handling to Group B service functions
- Fix dict mutation in relative_rotation (immutable pattern)
- Extract _classify_rrg_quadrant helper function
- Fix type builtin shadow in routes_economy (type -> gdp_type)
- Fix falsy int guard (if year: -> if year is not None:)
- Remove user input echo from error messages

routes_economy.py

@@ -23,10 +23,10 @@ async def macro_cpi(country: str = Query(default="united_states", max_length=50,
 @router.get("/macro/gdp", response_model=ApiResponse)
 @safe
 async def macro_gdp(
-    type: str = Query(default="real", pattern="^(nominal|real|forecast)$"),
+    gdp_type: str = Query(default="real", pattern="^(nominal|real|forecast)$"),
 ):
     """GDP: nominal, real, or forecast."""
-    data = await economy_service.get_gdp(gdp_type=type)
+    data = await economy_service.get_gdp(gdp_type=gdp_type)
     return ApiResponse(data=data)