feat: add backend configuration and windows utilities, and initialize frontend dependencies

main_instance_stub.go

@@ -5,6 +5,22 @@ package main
 // secondInstanceWake is unused on Windows (second-instance UX not wired here).
 var secondInstanceWake = make(chan struct{}, 8)
 
-func tryNotifyRunningInstanceToShow() {}
+// secondInstanceCommand is unused on Windows (second-instance UX not wired here).
+var secondInstanceCommand = make(chan byte, 16)
+
+const (
+	instanceCmdShow   byte = 1
+	instanceCmdStart  byte = 2
+	instanceCmdStop   byte = 3
+	instanceCmdToggle byte = 4
+)
+
+func tryNotifyRunningInstanceToShow() bool {
+	return false
+}
+
+func tryNotifyRunningInstanceAction(action string) bool {
+	return false
+}
 
 func runSecondInstanceListener() {}