fix: 最新公告防重入覆盖整个函数，推送改为时间升序间隔1秒

- 防重入锁移到函数入口，60秒内重复点击直接忽略，避免企微重试导致重复推送
- 取最新6条后按 publish_date 升序推送，企微向上滑即为时间正序
- 每条间隔1秒发送

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/wechat/handler.py

@@ -243,24 +243,25 @@ class WeChatMessageHandler:
     async def _handle_latest_announcements(self, from_user: str) -> str | None:
         global _last_latest_time
         from app.api.deps import get_db, get_crawl_service
-        from sqlalchemy import select, desc, or_
+        from sqlalchemy import select, asc, or_
         from app.models.announcement import Announcement
 
-        try:
-            # 防重入：60秒内只爬取一次
+        # 防重入：60秒内整个函数只执行一次（含推送）
         async with _latest_lock:
             now = time.monotonic()
-                do_crawl = (now - _last_latest_time) >= 60
-                if do_crawl:
+            if (now - _last_latest_time) < 60:
+                logger.info("最新公告请求被忽略（防重入）")
+                return None
             _last_latest_time = now
 
-            if do_crawl:
+        try:
             await self.client.send_text("正在获取最新公告，请稍候...", from_user)
             service = get_crawl_service()
             await service.run_all()
 
-            # 查：广西政采网关键词匹配 + 大化县政府网全部
+            # 查：广西政采网关键词匹配 + 大化县政府网全部，取最新6条后按时间升序推送
             async for db in get_db():
+                from sqlalchemy import select, desc, or_
                 result = await db.execute(
                     select(Announcement)
                     .where(or_(
@@ -276,7 +277,8 @@ class WeChatMessageHandler:
                     await self.client.send_text("暂无公告", from_user)
                     return None
 
-                for ann in items:
+                # 按时间升序推送，企微里向上滑即为时间正序
+                for ann in sorted(items, key=lambda a: a.publish_date):
                     title = ann.title if len(ann.title) <= 128 else ann.title[:125] + "..."
                     purchase_name = ann.purchase_name or ""
                     if len(purchase_name) > 25:
@@ -285,6 +287,7 @@ class WeChatMessageHandler:
                     source_name = ann.source_name or ann.source_code or ""
                     description = f"{source_name} | {purchase_name} | {time_str}"
                     await self.client.send_textcard(title, description, ann.content_url or "", from_user)
+                    await asyncio.sleep(1)
         except Exception as e:
             logger.error(f"查询最新公告失败: {e}")
             await self.client.send_text("查询失败，请稍后再试", from_user)