chore(quality): apply ruff autofixes and formatting (29 fixes, 41 files reformatted)

backend/app/core/config.py

@@ -1,7 +1,6 @@
 """Application configuration using pydantic-settings."""
 
 from pydantic_settings import BaseSettings
-from typing import Optional
 
 
 class Settings(BaseSettings):
@@ -38,7 +37,9 @@ class Settings(BaseSettings):
     @property
     def cors_origin_list(self) -> list[str]:
         """Return CORS origins as a list."""
-        return [origin.strip() for origin in self.CORS_ORIGINS.split(",") if origin.strip()]
+        return [
+            origin.strip() for origin in self.CORS_ORIGINS.split(",") if origin.strip()
+        ]
 
     model_config = {
         "env_file": ".env",