Refactor code structure for improved readability and maintainability

app/auth.py

@@ -0,0 +1,20 @@
+import secrets
+from typing import Annotated
+
+from fastapi import Depends, HTTPException, status
+from fastapi.security import APIKeyHeader
+
+from app.config import Settings, get_settings
+
+api_key_header = APIKeyHeader(name="X-API-Key", auto_error=False)
+
+
+async def require_api_key(
+    supplied_key: Annotated[str | None, Depends(api_key_header)],
+    current_settings: Annotated[Settings, Depends(get_settings)],
+) -> None:
+    if supplied_key is None or not secrets.compare_digest(supplied_key, current_settings.api_key):
+        raise HTTPException(
+            status_code=status.HTTP_401_UNAUTHORIZED,
+            detail="Invalid or missing API key",
+        )