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/auth/auth_helpers_test.go

@@ -0,0 +1,18 @@
+package auth
+
+import (
+	"time"
+
+	"github.com/golang-jwt/jwt/v5"
+)
+
+func jwtRegisteredExpired() jwt.RegisteredClaims {
+	return jwt.RegisteredClaims{
+		ExpiresAt: jwt.NewNumericDate(time.Now().Add(-time.Hour)),
+		Issuer:    "everypublish",
+	}
+}
+
+func signExpired(secret string, claims AccessClaims) (string, error) {
+	return jwt.NewWithClaims(jwt.SigningMethodHS256, claims).SignedString([]byte(secret))
+}