rebuild: split core into separate repo; move wg-go integration to internal/ctr/corebind

- go.mod: require git.zkcoi.com/zkcoi/meshray/core, replace => ../Meshray
- internal/ctr/corebind: EnhancedBind + registry + adapter (wg-go integration isolated)
- cmd/mr-wg migrated from old core/cmd/meshray-core
- core/ removed; CHANGELOG updated; fix checkdb vet warning

internal/api/server.go

@@ -61,6 +61,17 @@ func NewServer(cfg *config.Config, logger *zap.Logger, dbStore *sqlite.Store) (*
 		store:  dbStore,
 	}
 
+	// 首次启动初始化管理员账户（已存在则跳过，仅新建时返回随机密码）
+	userService := service.NewUserService(dbStore)
+	if uname, pwd, ierr := userService.InitializeAdmin(); ierr == nil {
+		if pwd != "" {
+			server.logger.Warn("已创建默认管理员账户，请尽快登录并修改密码",
+				zap.String("username", uname), zap.String("password", pwd))
+		}
+	} else {
+		server.logger.Error("初始化管理员账户失败", zap.Error(ierr))
+	}
+
 	// 注册中间件
 	server.registerMiddleware()
 
@@ -142,7 +153,9 @@ func (s *Server) registerRoutes() error {
 			}
 
 			// 尝试直接提供文件
+			// staticFS 已通过 fs.Sub 剥离 "static" 前缀，需先去掉路径中的 "static/"
 			filePath := strings.TrimPrefix(path, "/")
+			filePath = strings.TrimPrefix(filePath, "static/")
 			if filePath == "" {
 				filePath = "index.html"
 			}