feat: rebuild rss-news backend, admin ui, and legal extraction pipeline

backend/app/config.py

@@ -0,0 +1,29 @@
+from functools import lru_cache
+
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    # Prefer backend-specific env file to avoid collisions with legacy root .env
+    model_config = SettingsConfigDict(
+        env_file=("backend/.env", ".env"),
+        env_file_encoding="utf-8",
+        extra="ignore",
+    )
+
+    app_env: str = "development"
+    app_name: str = "rss-news-backend"
+    app_secret_key: str = "replace-with-a-long-random-secret"
+
+    app_admin_username: str = "admin"
+    app_admin_password: str = "change-me"
+
+    session_cookie_name: str = "rss_news_session"
+    session_max_age_seconds: int = 28800
+
+    app_db_path: str = "backend/data/rss_news.db"
+
+
+@lru_cache(maxsize=1)
+def get_settings() -> Settings:
+    return Settings()