修复: 粘贴图失效与SFTP串台回退等一批问题

粘贴图根修(Ctrl+V直读系统剪贴板,不再依赖不可靠的paste事件)/SFTP串台双刀(拨号期禁回退本机+盘符路径自动回根)/PDF导出目录设置与文案带落盘路径/性能批(连接保存下载防重/md渲染防抖+预热/hljs按需加载/审计锁外置/快捷方式解析超时/webview-watch可停)/前端62类型错清零(含keyPath蛇形字段炸弹)/目录图标字段错位修复

internal/sftp/client.go

@@ -10,11 +10,16 @@ import (
 
 	"github.com/pkg/sftp"
 	"golang.org/x/crypto/ssh"
+	"u-desk/internal/common"
 )
 
 // 连接建立全流程（拨号+认证+SFTP 子系统）的总超时预算
 const connectTimeout = 10 * time.Second
 
+// 拨号独立预算，小于总预算：冷连接卡死大多发生在 TCP 拨号，
+// 独立预算保证握手认证阶段始终有剩余 deadline 可用
+const dialTimeout = 6 * time.Second
+
 // 保活参数：周期发送 keepalive 并等待回复，超过 keepaliveReplyWait 未回复判定连接已死
 const (
 	keepaliveInterval  = 30 * time.Second
@@ -45,7 +50,8 @@ func GetManager() *Manager {
 }
 
 // Connect 创建或复用 SFTP 连接
-func (m *Manager) Connect(config *Config) (*Client, error) {
+// onStage 在连接各阶段推进时回调（dial/auth/channel），可为 nil
+func (m *Manager) Connect(config *Config, onStage func(stage string)) (*Client, error) {
 	key := fmt.Sprintf("%s:%d", config.Host, config.Port)
 
 	m.mu.Lock()
@@ -60,7 +66,7 @@ func (m *Manager) Connect(config *Config) (*Client, error) {
 		m.clients.Delete(key)
 	}
 
-	c, err := newClient(config)
+	c, err := newClient(config, onStage)
 	if err != nil {
 		return nil, err
 	}
@@ -102,8 +108,8 @@ func (m *Manager) Shutdown() {
 // --- 内部 ---
 
 // newClient 建立连接并启动保活循环
-func newClient(config *Config) (*Client, error) {
-	c, err := buildClient(config)
+func newClient(config *Config, onStage func(stage string)) (*Client, error) {
+	c, err := buildClient(config, onStage)
 	if err != nil {
 		return nil, err
 	}
@@ -112,7 +118,14 @@ func newClient(config *Config) (*Client, error) {
 }
 
 // buildClient 拨号+认证+SFTP 子系统建立（全程受 connectTimeout 约束），不启动保活
-func buildClient(config *Config) (*Client, error) {
+// onStage 标记各阶段开始：dial=拨号、auth=认证、channel=建通道；SSH 协议链路串行，
+// 无法并行加速，分步回调让前端可见当前卡点
+func buildClient(config *Config, onStage func(stage string)) (*Client, error) {
+	notify := func(stage string) {
+		if onStage != nil {
+			onStage(stage)
+		}
+	}
 	sshConfig := &ssh.ClientConfig{
 		Config: ssh.Config{
 			KeyExchanges: []string{
@@ -160,14 +173,17 @@ func buildClient(config *Config) (*Client, error) {
 
 	// JoinHostPort 保证 IPv6 主机地址被方括号包裹，fmt 拼接对 IPv6 产生非法地址
 	addr := net.JoinHostPort(config.Host, strconv.Itoa(config.Port))
-	// 拨号与认证、SFTP 子系统握手共享同一总超时预算，认证阶段无界挂起由 deadline 掐断
+	// 总 deadline 从拨号前起算：拨号占独立 6s 预算，认证与 SFTP 子系统握手受剩余总预算约束，
+	// 认证阶段无界挂起由 deadline 掐断
 	deadline := time.Now().Add(connectTimeout)
-	sshConn, err := net.DialTimeout("tcp", addr, connectTimeout)
+	notify("dial")
+	sshConn, err := net.DialTimeout("tcp", addr, dialTimeout)
 	if err != nil {
 		return nil, &ConnectionError{Op: "dial", Err: err}
 	}
 	sshConn.SetDeadline(deadline)
 
+	notify("auth")
 	sshConnConn, chans, reqs, err := ssh.NewClientConn(sshConn, addr, sshConfig)
 	if err != nil {
 		sshConn.Close()
@@ -176,6 +192,7 @@ func buildClient(config *Config) (*Client, error) {
 
 	sshClient := ssh.NewClient(sshConnConn, chans, reqs)
 
+	notify("channel")
 	sftpClient, err := sftp.NewClient(sshClient)
 	sshConn.SetDeadline(time.Time{})
 	if err != nil {
@@ -196,7 +213,7 @@ func (c *Client) startKeepalive() {
 	stop := make(chan struct{})
 	sshClient := c.sshClient
 	c.stopKeep = stop
-	go func() {
+	common.Go("sftp-keepalive", func() {
 		t := time.NewTicker(keepaliveInterval)
 		defer t.Stop()
 		for {
@@ -210,16 +227,16 @@ func (c *Client) startKeepalive() {
 				return
 			}
 		}
-	}()
+	})
 }
 
 // sshKeepalive 发送一次 keepalive 请求并限时等待回复，超时或出错视作连接已死
 func sshKeepalive(sshClient *ssh.Client, wait time.Duration) bool {
 	done := make(chan error, 1)
-	go func() {
+	common.Go("sftp-keepalive-probe", func() {
 		_, _, err := sshClient.SendRequest("keepalive@openssh.com", true, nil)
 		done <- err
-	}()
+	})
 	select {
 	case err := <-done:
 		return err == nil
@@ -295,7 +312,8 @@ func (c *Client) WithRetry(fn func(*sftp.Client) error) error {
 
 func (c *Client) reconnect() error {
 	// 用 buildClient 而非 newClient，避免保活循环绑定到即将丢弃的临时容器
-	nc, err := buildClient(c.config)
+	// 后台重连无阶段展示需求，回调传 nil
+	nc, err := buildClient(c.config, nil)
 	if err != nil {
 		return err
 	}

internal/sftp/service.go

@@ -844,9 +844,9 @@ func (s *Service) GetSystemInfo(connID string) (map[string]interface{}, error) {
 		out, e := c.RunCommand(cmd)
 		results <- cmdResult{key, out, e}
 	}
-	go runCmd("df", "df -B1 / 2>/dev/null | tail -1")
-	go runCmd("mem", "free -b 2>/dev/null | grep -E '^Mem:' || cat /proc/meminfo 2>/dev/null | head -2")
-	go runCmd("cpu", "top -bn1 | grep 'Cpu(s)' | awk '{print $2}' | cut -d'%' -f1")
+	common.Go("sftp-cmd-df", func() { runCmd("df", "df -B1 / 2>/dev/null | tail -1") })
+	common.Go("sftp-cmd-mem", func() { runCmd("mem", "free -b 2>/dev/null | grep -E '^Mem:' || cat /proc/meminfo 2>/dev/null | head -2") })
+	common.Go("sftp-cmd-cpu", func() { runCmd("cpu", "top -bn1 | grep 'Cpu(s)' | awk '{print $2}' | cut -d'%' -f1") })
 
 	var dfOut, memOut, cpuOut string
 	hasErr := false