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/singleinstance/singleinstance_windows.go

@@ -0,0 +1,68 @@
+//go:build windows
+
+package singleinstance
+
+import (
+	"fmt"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+var (
+	user32            = windows.NewLazySystemDLL("user32.dll")
+	procFindWindow    = user32.NewProc("FindWindowW")
+	procShowWindow    = user32.NewProc("ShowWindow")
+	procSetForeground = user32.NewProc("SetForegroundWindow")
+	procIsIconic      = user32.NewProc("IsIconic")
+)
+
+const (
+	swShow    = 5
+	swRestore = 9
+)
+
+// Lock acquires a per-user mutex. If another Navis holds it, activates that
+// window (title "Navis") and returns ErrAlreadyRunning.
+func Lock(appName string) (func(), error) {
+	if appName == "" {
+		appName = "Navis"
+	}
+	name, err := windows.UTF16PtrFromString("Local\\" + appName + "SingleInstance")
+	if err != nil {
+		return nil, err
+	}
+	handle, err := windows.CreateMutex(nil, false, name)
+	if err == windows.ERROR_ALREADY_EXISTS {
+		if handle != 0 {
+			_ = windows.CloseHandle(handle)
+		}
+		activateWindow(appName)
+		return nil, ErrAlreadyRunning
+	}
+	if err != nil {
+		return nil, fmt.Errorf("singleinstance: %w", err)
+	}
+	return func() {
+		_ = windows.ReleaseMutex(handle)
+		_ = windows.CloseHandle(handle)
+	}, nil
+}
+
+func activateWindow(title string) {
+	t, err := windows.UTF16PtrFromString(title)
+	if err != nil {
+		return
+	}
+	hwnd, _, _ := procFindWindow.Call(0, uintptr(unsafe.Pointer(t)))
+	if hwnd == 0 {
+		return
+	}
+	iconic, _, _ := procIsIconic.Call(hwnd)
+	if iconic != 0 {
+		procShowWindow.Call(hwnd, swRestore)
+	} else {
+		procShowWindow.Call(hwnd, swShow)
+	}
+	procSetForeground.Call(hwnd)
+}