Release 3.8.2.11: idle rev-cache, port-safe Connect, single-instance tray UX.

Faster unchanged polls; orphan-core cleanup on listen ports; clearer busy-port errors; cores only from binDir; incremental server list; CSP without Google Fonts; single-instance activates existing window; close-to-tray without kill-others or balloon.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/core/manager.go

@@ -16,6 +16,8 @@ import (
 	"vpnclient/internal/config"
 	"vpnclient/internal/corebin"
 	"vpnclient/internal/linknorm"
+	"vpnclient/internal/listenutil"
+	"vpnclient/internal/netcheck"
 	"vpnclient/internal/protocols/awg"
 	"vpnclient/internal/protocols/hysteria2"
 	"vpnclient/internal/protocols/naive"
@@ -108,12 +110,19 @@ func (m *Manager) Connect(ctx context.Context, profileName string) error {
 	stderr := m.stderr
 	m.mu.Unlock()
 
+	socksHP, _ := profileCopy.SOCKSListenHostPort()
+	httpHP, _ := profileCopy.HTTPListenHostPort()
+	listenAddrs := listenutil.ListenAddrs(socksHP, httpHP)
+	if err := listenutil.EnsureFree(binDir, listenAddrs...); err != nil {
+		return err
+	}
+
 	engine, err := m.newEngine(profileCopy.Protocol)
 	if err != nil {
 		return err
 	}
 	if err := engine.Start(ctx, profileCopy, binDir); err != nil {
-		return err
+		return listenutil.ClassifyStartFailure(string(profileCopy.Protocol), err, listenAddrs...)
 	}
 
 	m.mu.Lock()
@@ -626,6 +635,22 @@ func (m *Manager) Profiles() []config.ProfileInfo {
 	return m.cfg.ListProfiles()
 }
 
+// PingTargets returns name/protocol/host endpoints without copying proxy secrets.
+func (m *Manager) PingTargets() []netcheck.Target {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	list := m.cfg.ListProfilesForPoll()
+	out := make([]netcheck.Target, 0, len(list))
+	for _, p := range list {
+		out = append(out, netcheck.Target{
+			Name:     p.Name,
+			Protocol: config.Protocol(p.Protocol),
+			Host:     p.Host,
+		})
+	}
+	return out
+}
+
 // Hy2Options are editable Hysteria 2 extras for the active profile.
 type Hy2Options struct {
 	Congestion    string `json:"congestion"`