initialize Electron desktop app and remove unused files

tests/client/fixtures/script-setup-let-assignment.vue

@@ -0,0 +1,21 @@
+<script setup lang="ts">
+// 测试夹具：验证 <script setup> 的 let 绑定在模板内联语句里能否写回。
+// 与 McpManagerView.vue 的 `_autoRetryCount` 同一形态。
+let counter = 0
+const observed: number[] = []
+
+function bump() {
+  counter++
+  observed.push(counter)
+}
+
+function read() {
+  observed.push(counter)
+}
+</script>
+
+<template>
+  <button class="bump" @click="bump()">bump</button>
+  <!-- 先把 counter 推到非 0，再内联复位后读取 —— 这样「复位是否生效」才有区分度 -->
+  <button class="reset-read" @click="counter = 0; read()">reset+read</button>
+</template>