Initial Navis client with NaiveProxy, profiles, ping and git updates

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

cmd/vpnapp/main_other.go

@@ -0,0 +1,13 @@
+//go:build !windows
+
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+func main() {
+	fmt.Fprintln(os.Stderr, "Navis GUI is Windows-only (WebView2). Use vpnclient CLI on this platform.")
+	os.Exit(1)
+}