feat: add preferred debug port planning

cmd/chub/main.go

@@ -164,7 +164,7 @@ func runWindow(logger *slog.Logger) {
 				shell.SetProxies(proxyOptions(saved.Proxies))
 				rows := make([]ui.InstanceRow, 0, len(saved.Instances))
 				for _, item := range saved.Instances {
-					rows = append(rows, ui.InstanceRow{ID: item.ID, Name: item.Name, Browser: browserLabel(item.Launch.Kind), UserDataDir: item.Launch.UserDataDir, TargetURL: item.Launch.TargetURL, ProxyID: item.ProxyID, Status: "已退出"})
+					rows = append(rows, ui.InstanceRow{ID: item.ID, Name: item.Name, Browser: browserLabel(item.Launch.Kind), UserDataDir: item.Launch.UserDataDir, TargetURL: item.Launch.TargetURL, ProxyID: item.ProxyID, PreferredRemoteDebugPort: item.PreferredRemoteDebugPort, Status: "已退出"})
 				}
 				shell.SetInstances(rows)
 				shell.OnSave(func(value ui.SettingsState) {
@@ -493,7 +493,11 @@ func (s instanceStarter) Start(ctx context.Context, row ui.InstanceRow, settings
 	if err != nil {
 		return ui.InstanceStartOutcome{}, fmt.Errorf("无法找到%s可执行文件：%w", browserLabel(kind), err)
 	}
-	port, err := s.portAllocator.FindAvailableRemoteDebugPort(ctx, settings.RemoteDebugStartPort)
+	startPort := row.PreferredRemoteDebugPort
+	if !domain.ValidRemoteDebugPort(startPort) {
+		startPort = settings.RemoteDebugStartPort
+	}
+	port, err := findAvailableUnreservedRemoteDebugPort(ctx, s.portAllocator, startPort, settings.ReservedRemoteDebugPorts)
 	if err != nil {
 		return ui.InstanceStartOutcome{}, fmt.Errorf("无法分配本地调试端口：%w", err)
 	}
@@ -556,6 +560,7 @@ func mergeInstanceConfig(existing []config.Instance, rows []ui.InstanceRow) []co
 		item.Launch.UserDataDir = row.UserDataDir
 		item.Launch.TargetURL = row.TargetURL
 		item.ProxyID = row.ProxyID
+		item.PreferredRemoteDebugPort = row.PreferredRemoteDebugPort
 		if item.ProxyID != "" {
 			item.Launch.ProxyServer = ""
 		}
@@ -565,6 +570,38 @@ func mergeInstanceConfig(existing []config.Instance, rows []ui.InstanceRow) []co
 	return updated
 }
 
+func findAvailableUnreservedRemoteDebugPort(ctx context.Context, allocator browser.RemoteDebugPortAllocator, start int, reserved []int) (int, error) {
+	if allocator == nil {
+		return 0, errors.New("remote debug port allocator is required")
+	}
+	if !domain.ValidRemoteDebugPort(start) {
+		return 0, fmt.Errorf("invalid remote debug start port %d", start)
+	}
+	reservedSet := make(map[int]struct{}, len(reserved))
+	for _, port := range reserved {
+		if domain.ValidRemoteDebugPort(port) {
+			reservedSet[port] = struct{}{}
+		}
+	}
+	for candidate := start; candidate <= domain.MaxRemoteDebugPort; {
+		port, err := allocator.FindAvailableRemoteDebugPort(ctx, candidate)
+		if err != nil {
+			return 0, err
+		}
+		if !domain.ValidRemoteDebugPort(port) || port < candidate {
+			return 0, fmt.Errorf("port allocator returned invalid port %d", port)
+		}
+		if _, reservedByOtherInstance := reservedSet[port]; !reservedByOtherInstance {
+			return port, nil
+		}
+		if port == domain.MaxRemoteDebugPort {
+			break
+		}
+		candidate = port + 1
+	}
+	return 0, errors.New("no unreserved local remote debug port is available")
+}
+
 func mergeProxyConfig(existing []config.ProxyProfile, options []ui.ProxyOption) []config.ProxyProfile {
 	byID := make(map[string]config.ProxyProfile, len(existing))
 	for _, profile := range existing {