chore(lint): apply ruff --fix (4443 auto-fixes)

Auto-fixed categories:
- F401: unused imports removed
- I001: import blocks sorted
- W293: trailing whitespace stripped
- UP035: deprecated typing imports replaced
- SIM: simplify suggestions applied
- ARG: unused args prefixed with underscore
- T201: print statements removed
- F841: unused variables removed
- RUF059: unpacked variables prefixed

Remaining ~1500 unfixable errors (C901, B904, N806, E402) require manual work.

Backend smoke tests: 13/13 passed.

backend/src/core/auth/config.py

@@ -9,6 +9,7 @@
 from pydantic import Field
 from pydantic_settings import BaseSettings
 
+
 # #region AuthConfig [TYPE Class]
 # @BRIEF Holds authentication-related settings.
 # @PRE:     Environment variables may be provided via .env file.
@@ -31,7 +32,7 @@ class AuthConfig(BaseSettings):
     ADFS_CLIENT_ID: str = Field(default="", env="ADFS_CLIENT_ID")
     ADFS_CLIENT_SECRET: str = Field(default="", env="ADFS_CLIENT_SECRET")
     ADFS_METADATA_URL: str = Field(default="", env="ADFS_METADATA_URL")
-    
+
     class Config:
         env_file = ".env"
         extra = "ignore"