chore: 集成 LLM 增强 — config/main/articles schema/workers + .env.example 加 Agnes 配置

backend/app/schemas/article.py

@@ -46,14 +46,21 @@ class ArticleDetail(BaseModel):
     title_zh: str | None = None
     body_zh_html: str | None = None
     body_zh_text: str | None = None
+    body_zh_formatted: str | None = None  # LLM 排版后
     summary_zh: str | None = None
     lang_src: str | None = None
     author: str | None = None
     image_url: str | None = None
+    image_ai_url: str | None = None  # LLM 生成的插图
     translation_status: str
     translation_engine: str | None = None
     translated_at: datetime | None = None
+    # === LLM 增强状态 + 内容 ===
     category: str | None = None
+    format_status: str | None = None  # pending/ok/failed/n/a
+    classify_status: str | None = None
+    image_ai_status: str | None = None
+    commentary_status: str | None = None
     commentary: str | None = None
     entities: dict | None = None
     sentiment: float | None = None