fix(api): resolve mypy strict errors in rate limiter and health check

- rate_limit: make the decorator generic over the handler return type so
  endpoints returning a response model (e.g. TokenResponse) type-check
- main: drop now-unused redis ping type:ignore (redis 8 ships py.typed)

Co-Authored-By: First Fluke <our.first.fluke@gmail.com>

Author: gracefullight

apps/api/src/lib/rate_limit.py

@@ -6,7 +6,7 @@
 from collections.abc import Awaitable, Callable
 from dataclasses import dataclass, field
 from functools import wraps
-from typing import TYPE_CHECKING, cast
+from typing import TYPE_CHECKING, TypeVar, cast
 
 from fastapi import HTTPException, Request, status
 from fastapi.responses import Response
@@ -19,6 +19,10 @@
 
 logger = get_logger(__name__)
 
+# Return type of the decorated endpoint (e.g. a Pydantic response model),
+# preserved so the rate limiter does not narrow handler return types to Response.
+R = TypeVar("R")
+
 
 @dataclass
 class RateLimitConfig:
@@ -224,7 +228,7 @@ def rate_limit(
     requests: int = 100,
     window: int = 60,
     key_func: Callable[[Request], str] | None = None,
-) -> Callable[[Callable[..., Awaitable[Response]]], Callable[..., Awaitable[Response]]]:
+) -> Callable[[Callable[..., Awaitable[R]]], Callable[..., Awaitable[R]]]:
     """
     Rate limit decorator for FastAPI endpoints.
 
@@ -243,10 +247,10 @@ async def get_resource():
     actual_key_func = key_func or default_key_func
 
     def decorator(
-        func: Callable[..., Awaitable[Response]],
-    ) -> Callable[..., Awaitable[Response]]:
+        func: Callable[..., Awaitable[R]],
+    ) -> Callable[..., Awaitable[R]]:
         @wraps(func)
-        async def wrapper(*args: object, **kwargs: object) -> Response:
+        async def wrapper(*args: object, **kwargs: object) -> R:
             # Find request in args/kwargs
             request: Request | None = None
             for arg in args:

apps/api/src/main.py

@@ -172,7 +172,7 @@ async def check_redis() -> ServiceStatus | None:
         import redis.asyncio as redis
 
         client = redis.from_url(settings.REDIS_URL)
-        await client.ping()  # type: ignore[misc]
+        await client.ping()
         await client.aclose()
         latency = (time.perf_counter() - start) * 1000
         return ServiceStatus(status="healthy", latency_ms=round(latency, 2))