fix(runtime): e2e 发现的 3 个 bug 修复

- download: desktop_download_apps SingleChildScrollView 加 primary:true (Scrollbar 缺 ScrollPosition)
- contact-stores: checkDomainAvailability async 后 setState 加 mounted 保护 (dispose 后 setState)
- buy-service: _loadData 加 data 结构校验 + mounted 保护 (API 400 无效参数时 data 为错误结构 -> RangeError)

tools/e2e/node_modules/playwright/lib/agents/copilot-setup-steps.yml

@@ -0,0 +1,34 @@
+name: "Copilot Setup Steps"
+
+on:
+  workflow_dispatch:
+  push:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+  pull_request:
+    paths:
+      - .github/workflows/copilot-setup-steps.yml
+
+jobs:
+  copilot-setup-steps:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+
+    steps:
+    - uses: actions/checkout@v6
+
+    - uses: actions/setup-node@v6
+      with:
+        node-version: lts/*
+
+    - name: Install dependencies
+      run: npm ci
+
+    - name: Install Playwright Browsers
+      run: npx playwright install --with-deps
+
+    # Customize this step as needed
+    - name: Build application
+      run: npx run build