feat: 记住上次选中的配置，下次启动自动选中

- 启用 AppConfig.DefaultProfileID 字段（此前声明但未使用）
- 启动时 loadProfiles() 优先选中上次记录的配置，找不到则回退到第一个
- 切换配置时立即持久化到 config.yml，防止崩溃丢失
- 使用 Profile ID 而非名称，避免重命名后失效

Makefile

@@ -11,7 +11,7 @@ GO          = go
 CGO_ENABLED = 1
 WINDRES     ?= x86_64-w64-mingw32-windres
 MINGW_CC    ?= x86_64-w64-mingw32-gcc
-SEMVER      ?= 0.4.1
+SEMVER      ?= 0.4.3
 GIT_HASH    = $(shell git rev-parse --short HEAD 2>/dev/null || echo unknown)
 VERSION     = $(SEMVER)-$(GIT_HASH)
 LDFLAGS     = -s -w -X lmvpn/internal/version.Version=$(VERSION)

internal/daemon/daemon.go

@@ -19,6 +19,7 @@ import (
 	"net"
 	"os"
 	"os/signal"
+	"sync"
 	"syscall"
 
 	"lmvpn/internal/ipc"
@@ -92,6 +93,7 @@ func chownToUser(path string, uid, gid int) {
 
 type daemon struct {
 	server  *ipc.Server
+	mu      sync.Mutex
 	session *vpn.SessionManager
 	cancel  context.CancelFunc
 }
@@ -109,8 +111,11 @@ func (d *daemon) handle(conn net.Conn, req ipc.Request) {
 		d.server.Close()
 		os.Exit(0)
 	case ipc.CmdStats:
-		if d.session != nil {
-			snap := d.session.Stats().Snapshot()
+		d.mu.Lock()
+		sess := d.session
+		d.mu.Unlock()
+		if sess != nil {
+			snap := sess.Stats().Snapshot()
 			d.server.Broadcast(ipc.Event{Event: ipc.EvStats, Stats: &snap})
 		}
 		_ = ipc.WriteOK(conn)
@@ -122,12 +127,14 @@ func (d *daemon) handle(conn net.Conn, req ipc.Request) {
 }
 
 func (d *daemon) startSession(conn net.Conn, req ipc.Request) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
 	if req.Config == nil {
 		_ = ipc.WriteErr(conn, "missing config")
 		return
 	}
 	if d.session != nil {
-		d.stopSession()
+		d.stopSessionLocked()
 	}
 
 	cfg := vpn.SessionConfig{
@@ -170,6 +177,12 @@ func (d *daemon) startSession(conn net.Conn, req ipc.Request) {
 }
 
 func (d *daemon) stopSession() {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	d.stopSessionLocked()
+}
+
+func (d *daemon) stopSessionLocked() {
 	if d.cancel != nil {
 		d.cancel()
 		d.cancel = nil

internal/ui/app.go

@@ -48,11 +48,12 @@ type App struct {
 	disconnectBtn *widget.Button
 
 	// State
-	mu             sync.Mutex
-	ipcClient      *ipc.Client
-	profiles       []model.ServerProfile
-	currentProfile *model.ServerProfile
-	langSetting    string
+	mu              sync.Mutex
+	ipcClient       *ipc.Client
+	profiles        []model.ServerProfile
+	currentProfile  *model.ServerProfile
+	defaultProfileID int64
+	langSetting     string
 }
 
 // Run initialises and starts the GUI application.
@@ -84,6 +85,7 @@ func Run() {
 		db:                store,
 		kc:                keychain.New(),
 		langSetting:       cfg.Language,
+		defaultProfileID:  cfg.DefaultProfileID,
 		listSelectedIndex: -1,
 	}
 
@@ -144,8 +146,21 @@ func (a *App) loadProfiles() {
 	names := a.profileNames()
 	a.profileSelect.Options = names
 	if len(names) > 0 {
-		a.profileSelect.SetSelectedIndex(0)
-		a.selectProfileByName(names[0])
+		selected := false
+		if a.defaultProfileID > 0 {
+			for i := range a.profiles {
+				if a.profiles[i].ID == a.defaultProfileID {
+					a.profileSelect.SetSelectedIndex(i)
+					a.selectProfileByName(a.profiles[i].Name)
+					selected = true
+					break
+				}
+			}
+		}
+		if !selected {
+			a.profileSelect.SetSelectedIndex(0)
+			a.selectProfileByName(names[0])
+		}
 	} else {
 		a.currentProfile = nil
 		a.profileSelect.SetSelected("")
@@ -182,6 +197,26 @@ func (a *App) selectProfileByName(name string) {
 	}
 }
 
+// saveDefaultProfile persists the currently selected profile ID to the
+// config file so it can be restored on the next launch.
+func (a *App) saveDefaultProfile() {
+	if a.currentProfile == nil {
+		return
+	}
+	a.defaultProfileID = a.currentProfile.ID
+	cfg, err := config.Load()
+	if err != nil {
+		cfg = config.Default()
+	}
+	if cfg.DefaultProfileID == a.currentProfile.ID {
+		return
+	}
+	cfg.DefaultProfileID = a.currentProfile.ID
+	if err := config.Save(cfg); err != nil {
+		log.L().Error("save default profile", "error", err)
+	}
+}
+
 // onAddProfile shows a dialog to create a new profile.
 func (a *App) onAddProfile() {
 	a.showProfileDialog(nil)

internal/ui/view.go

@@ -39,6 +39,13 @@ func (a *App) setConnButtons(connectEnabled, disconnectEnabled bool) {
 	} else {
 		a.disconnectBtn.Disable()
 	}
+	if a.profileSelect != nil {
+		if connectEnabled {
+			a.profileSelect.Enable()
+		} else {
+			a.profileSelect.Disable()
+		}
+	}
 	a.setupTray()
 }
 
@@ -47,6 +54,7 @@ func (a *App) buildMainWindow() fyne.CanvasObject {
 	// Profile selector.
 	a.profileSelect = widget.NewSelect(a.profileNames(), func(sel string) {
 		a.selectProfileByName(sel)
+		a.saveDefaultProfile()
 	})
 
 	// Status display.
@@ -132,8 +140,13 @@ func (a *App) onConnect() {
 		}
 
 		a.mu.Lock()
+		oldClient := a.ipcClient
 		a.ipcClient = client
 		a.mu.Unlock()
+		if oldClient != nil {
+			_ = ipc.SendStop(oldClient)
+			oldClient.Close()
+		}
 
 		// Get password from keychain.
 		password, err := a.kc.GetPassword(a.currentProfile.Name)
@@ -190,13 +203,24 @@ func (a *App) onConnect() {
 func (a *App) onDisconnect() {
 	a.mu.Lock()
 	client := a.ipcClient
+	a.ipcClient = nil
 	a.mu.Unlock()
 	if client == nil {
 		return
 	}
 	_ = ipc.SendStop(client)
+	client.Close()
 	a.setConnButtons(true, false)
 	a.stateLabel.SetText(i18n.T("StateDisconnected"))
+	a.ipLabel.SetText(i18n.T("IpNone"))
+	a.ip6Label.SetText(i18n.T("Ip6None"))
+	a.uptimeLabel.SetText(i18n.T("UptimeNone"))
+	a.rxV4Label.SetText(i18n.T("RxV4Zero"))
+	a.txV4Label.SetText(i18n.T("TxV4Zero"))
+	a.rxV6Label.SetText(i18n.T("RxV6Zero"))
+	a.txV6Label.SetText(i18n.T("TxV6Zero"))
+	a.rxTotalLabel.SetText(i18n.T("RxTotalZero"))
+	a.txTotalLabel.SetText(i18n.T("TxTotalZero"))
 }
 
 // eventLoop reads IPC events from the daemon and updates the UI.
@@ -234,17 +258,33 @@ func (a *App) eventLoop() {
 		switch ev.Event {
 		case ipc.EvState:
 			fyne.Do(func() {
-				a.applyState(ev.State)
+				a.mu.Lock()
+				current := a.ipcClient
+				a.mu.Unlock()
+				if current == client {
+					a.applyState(ev.State)
+				}
 			})
 		case ipc.EvStats:
 			if ev.Stats != nil {
 				s := *ev.Stats
 				fyne.Do(func() {
-					a.applyStats(s)
+					a.mu.Lock()
+					current := a.ipcClient
+					a.mu.Unlock()
+					if current == client {
+						a.applyStats(s)
+					}
 				})
 			}
 		case ipc.EvError:
 			fyne.Do(func() {
+				a.mu.Lock()
+				current := a.ipcClient
+				a.mu.Unlock()
+				if current != client {
+					return
+				}
 				if ev.Code == "tls_error" {
 					showError(i18n.T("DlgTLSError"),
 						i18n.T("TLSErrorVerification")+"\n\n"+ev.Message, a.window)

internal/vpn/session.go

@@ -60,6 +60,7 @@ type SessionManager struct {
 	dev      tun.Device
 	routeMgr *route.Manager
 	conn     *transport.Conn
+	done     chan struct{}
 
 	// EWMA speed smoothing state. Only touched by reportStats (single
 	// goroutine), so no lock needed. ewma* fields hold the smoothed
@@ -106,6 +107,7 @@ func (sm *SessionManager) Connect(ctx context.Context, cfg SessionConfig) error
 	ctx, cancel := context.WithCancel(ctx)
 	sm.cancel = cancel
 	sm.running = true
+	sm.done = make(chan struct{})
 	sm.mu.Unlock()
 
 	go sm.run(ctx, cfg)
@@ -126,21 +128,32 @@ func (sm *SessionManager) Disconnect() {
 	if cancel != nil {
 		cancel()
 	}
-	// Close the transport to unblock the packet pump.
+	// Close the transport to unblock the WS->TUN goroutine.
 	sm.mu.Lock()
 	conn := sm.conn
+	dev := sm.dev
 	sm.mu.Unlock()
 	if conn != nil {
 		conn.Close()
 	}
+	// Close the TUN device to unblock the TUN->WS goroutine's dev.Read().
+	if dev != nil {
+		dev.Close()
+	}
+	// Wait for the run goroutine to fully exit so that cleanup
+	// (route removal, TUN teardown) is complete before returning.
+	if sm.done != nil {
+		<-sm.done
+	}
 }
 
 // run is the main session loop with exponential-backoff reconnection
 // and CDN IP failover.
 func (sm *SessionManager) run(ctx context.Context, cfg SessionConfig) {
 	fatal := false
+	defer close(sm.done)
 	defer func() {
-		if !fatal {
+		if !fatal && ctx.Err() == nil {
 			sm.setState(stats.StateDisconnected)
 		}
 	}()
@@ -154,6 +167,7 @@ func (sm *SessionManager) run(ctx context.Context, cfg SessionConfig) {
 
 	for {
 		if ctx.Err() != nil {
+			sm.cleanup()
 			return
 		}