Add editor exclusion defaults and newsletter filtering controls.

This makes it possible to exclude specific editors (e.g. Aranzinger) from edited-article results by default, including dashboard generation and scheduled SMTP runs.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/core/config.py

@@ -21,6 +21,7 @@ class Settings(BaseSettings):
     admin_bootstrap_reset: bool = False
     editor_tip_max_length: int = 10000
     highlights_max_length: int = 5000
+    default_excluded_users: str = "Aranzinger"
 
     model_config = SettingsConfigDict(env_file=".env", env_file_encoding="utf-8", extra="ignore")