feat: 平台配置表扩展配图/字数字段，微信公众号正文插入配图，合规检查从DB读规则

- PlatformConfig模型新增requires_image、image_count_min/max、image_width/height、min_words/max_words
- schemas.py同步PlatformConfigBase/Create/Update/Response新字段
- initial_data.py为三大平台填充初始值（微信需配图、字数800-1500等）
- database.py添加新列ALTER TABLE迁移
- platforms.html重写编辑弹窗（正确字段名+配图/字数设置）
- writer.py微信公众号文章正文h1后插入<img>占位
- compliance_checker.py接受platform_config参数，从DB读取规则替代硬编码
- compliance_optimizer.py启动时加载DB平台配置传入checker

scripts/compliance_optimizer.py

@@ -185,6 +185,17 @@ def optimize_article(html: str, platform: str, topic_data: Dict, remaining_issue
         logs.append(pol_log)
     return html, logs
 
+def _load_platform_configs() -> Dict[str, Dict]:
+    """从 DB 加载所有平台配置"""
+    from app.database import SessionLocal
+    from app.models import PlatformConfig
+    db = SessionLocal()
+    try:
+        configs = db.query(PlatformConfig).all()
+        return {c.platform: c.to_dict() for c in configs}
+    finally:
+        db.close()
+
 def main(topic_ids: List[str] = None):
     logger.info("=== 合规审查与优化开始 ===")
     llm_cfg = get_llm_config()
@@ -193,6 +204,9 @@ def main(topic_ids: List[str] = None):
     else:
         logger.info("LLM 配置: 使用环境变量默认值")
 
+    platform_configs = _load_platform_configs()
+    logger.info(f"已加载 {len(platform_configs)} 个平台配置")
+
     articles = get_articles_from_db(topic_ids)
     if not articles:
         logger.warning("未找到任何文章（可能尚未创作或同步到 DB）")
@@ -216,7 +230,8 @@ def main(topic_ids: List[str] = None):
             logger.warning(f"未找到选题: {topic_id}")
             continue
 
-        check_result = check_article(html, platform_dir, topic_data)
+        pc = platform_configs.get(platform_dir, {})
+        check_result = check_article(html, platform_dir, topic_data, platform_config=pc)
         issues = check_result['issues']
         score = check_result['score']
         label = f"{platform_dir}/{topic_id}"