refactor: improve code formatting and readability across multiple files

backend/tests/test_error_handling.py

@@ -3,10 +3,14 @@ from __future__ import annotations
 from fastapi import FastAPI, HTTPException
 from fastapi.testclient import TestClient
 from pydantic import BaseModel, Field
-
 from starlette.requests import Request
 
-from app.core.error_handling import REQUEST_ID_HEADER, _error_payload, _get_request_id, install_error_handling
+from app.core.error_handling import (
+    REQUEST_ID_HEADER,
+    _error_payload,
+    _get_request_id,
+    install_error_handling,
+)
 
 
 def test_request_validation_error_includes_request_id():

backend/tests/test_request_id_middleware.py

@@ -46,7 +46,9 @@ async def test_request_id_middleware_ignores_blank_client_header_and_generates_o
 
     assert isinstance(captured_request_id, str) and captured_request_id
     # Header should reflect the generated id, not the blank one.
-    values = [v for k, v in response_headers if k.lower() == REQUEST_ID_HEADER.lower().encode("latin-1")]
+    values = [
+        v for k, v in response_headers if k.lower() == REQUEST_ID_HEADER.lower().encode("latin-1")
+    ]
     assert values == [captured_request_id.encode("latin-1")]
 
 
@@ -81,5 +83,7 @@ async def test_request_id_middleware_does_not_duplicate_existing_header() -> Non
     assert start_headers is not None
 
     # Ensure the middleware did not append a second copy.
-    values = [v for k, v in start_headers if k.lower() == REQUEST_ID_HEADER.lower().encode("latin-1")]
+    values = [
+        v for k, v in start_headers if k.lower() == REQUEST_ID_HEADER.lower().encode("latin-1")
+    ]
     assert values == [b"already"]