完善站点运营设置：分路由管理、登录可见评论、邮件模板内联与关闭注册 SSR。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/middleware/ratelimit.go

@@ -13,6 +13,7 @@ func RateLimitMiddleware(rl *service.RateLimiter, rateType string) gin.HandlerFu
 	return func(c *gin.Context) {
 		key := rateType + ":" + c.ClientIP()
 		if !rl.Allow(key) {
+			c.Header("Retry-After", "60")
 			c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{"error": "请求过于频繁，请稍后再试"})
 			return
 		}
@@ -30,6 +31,7 @@ func RateLimitUserMiddleware(rl *service.RateLimiter, rateType string) gin.Handl
 		}
 		key := rateType + ":u:" + id
 		if !rl.Allow(key) {
+			c.Header("Retry-After", "60")
 			c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{"error": "操作过于频繁，请稍后再试"})
 			return
 		}