[client/ui] Replace fyne UI with Wails (rename ui-wails to ui)

Removes the legacy fyne-based client/ui implementation and renames the
Wails replacement (client/ui-wails) to take its place at client/ui. Go
imports, frontend bindings, CI workflows, goreleaser configs and the
windows .syso icon path are updated to follow the rename.

client/ui/build/windows/info.json

@@ -0,0 +1,15 @@
+{
+	"fixed": {
+		"file_version": "0.0.1"
+	},
+	"info": {
+		"0000": {
+			"ProductVersion": "0.0.1",
+			"CompanyName": "NetBird",
+			"FileDescription": "NetBird desktop client",
+			"LegalCopyright": "© 2026, My Company",
+			"ProductName": "NetBird",
+			"Comments": "This is a comment"
+		}
+	}
+}