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

main/components/HeaderProtonSupportWidget.vue

@@ -0,0 +1,16 @@
+<template>
+  <NuxtLink to="/settings/compat">
+    <HeaderWidget
+      v-if="appState && appState.umuState !== 'NotNeeded'"
+      :problem="notInstalled"
+    >
+      <img src="/proton-logo.png" class="relative z-50 size-5 brightness-[30%]" />
+    </HeaderWidget>
+  </NuxtLink>
+</template>
+
+<script setup lang="ts">
+const appState = useAppState();
+
+const notInstalled = appState.value?.umuState === "NotInstalled";
+</script>