Add unmaximize permission for restore button

src-tauri/capabilities/default.json

@@ -18,6 +18,7 @@
     "core:window:allow-is-visible",
     "core:window:allow-unminimize",
     "core:window:allow-maximize",
+    "core:window:allow-unmaximize",
     "core:window:allow-set-size",
     "core:window:allow-set-min-size",
     "core:window:allow-set-decorations",