server: Go 服务器（REST+WSS 网关+JWT+Argon2+配对+素材直链+任务状态机）；修复并发下线 send-on-closed-channel、下发查询 SQL 优先级、配对码原子占用、上传体积上限、JWT 默认密钥告警

server/internal/api/response/response.go

@@ -0,0 +1,29 @@
+package response
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// OK 统一成功返回
+func OK(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusOK, gin.H{"code": 0, "message": "ok", "data": data})
+}
+
+// Fail 统一失败返回
+func Fail(c *gin.Context, httpCode int, bizCode int, msg string) {
+	c.JSON(httpCode, gin.H{"code": bizCode, "message": msg, "data": nil})
+}
+
+// AuditMeta 处理器埋点元数据
+type AuditMeta struct {
+	Action   string      `json:"action"`
+	Resource string      `json:"resource"`
+	Detail   interface{} `json:"detail"`
+}
+
+// Audit 审计埋点声明（由 middleware.Audit 中间件落库）
+func Audit(c *gin.Context, action, resource string, detail interface{}) {
+	c.Set("audit", AuditMeta{Action: action, Resource: resource, Detail: detail})
+}