修复：weblive 协程 panic 防护、Mongo 空指针防护、直播状态轮询退避

Made-with: Cursor

server/handlers/homepage.go

@@ -47,6 +47,11 @@ func GetWebHomepage(c *gin.Context) {
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 	defer cancel()
 
+	if config.MongoClient == nil {
+		c.JSON(http.StatusOK, defaultHomepageData())
+		return
+	}
+
 	siteID := getOfficialSiteID(ctx)
 	if siteID == "" {
 		c.JSON(http.StatusOK, defaultHomepageData())