Async downloader, better Proton support (#183)

* feat: async downloader + other fixes

* feat: windows command parsing + use library path for install path

* feat: better proton support

* feat: style fixes and store button now uses in-app

* feat: emulator rename + umu emulator fix

* feat: bring process creation inline with docs

* fix: clippy

desktop/main/package.json

@@ -14,6 +14,7 @@
     "@heroicons/vue": "^2.1.5",
     "@nuxtjs/tailwindcss": "^6.12.2",
     "@tauri-apps/api": "^2.9.1",
+    "@tauri-apps/plugin-dialog": "^2.6.0",
     "@tauri-apps/plugin-os": "^2.3.2",
     "@tauri-apps/plugin-shell": "^2.3.3",
     "koa": "^2.16.1",