fix: 三平台内容差异化 + admin敏感词管理表格化

- writer.py: _expand_section() 去除 <100字阈值，始终调用 LLM 平台专属扩写
- prompt_loader.py: 新增 section_expansion_zhihu/wechat/xiaohongshu 三个独立 prompt
- admin.html: 配置管理标签页 + 敏感词/清理规则子标签 + 敏感词表格化管理(编辑/删除)
- config_items.py: PUT /sensitive-words/{id} 支持更新 word/category
- compliance_checker.py: AI 套话从 DB 加载 + 人称规则修正
- initial_data.py: PlatformConfig 字数迁移 + 新种子
- 各前端页面: LLM 配置 rate_limit 字段 + 供应商列表排序

scripts/db_helper.py

@@ -89,8 +89,14 @@ def update_topic_status(topic_id: str, status: str, compliance_score: Optional[i
             topic.compliance_score = compliance_score
         if reviewed_at is not None:
             topic.reviewed_at = reviewed_at
-        if status in ['ready', 'published']:
+        if status == 'review' and topic.generated_at is None:
             topic.generated_at = datetime.now()
+            topic.reviewed_at = topic.reviewed_at or datetime.now()
+        if status == 'ready':
+            topic.ready_at = datetime.now().date()
+            topic.reviewed_at = topic.reviewed_at or datetime.now()
+        if status == 'published':
+            topic.published_at = datetime.now().date()
         db.commit()
         return True
     finally:
@@ -243,7 +249,6 @@ def save_article(topic_id: str, platform: str, html_content: str, db: Optional[S
         now = datetime.now()
         if existing:
             existing.html_content = html_content
-            existing.compliance_score = existing.compliance_score
         else:
             article = Article(
                 id=article_id,