ci: add test for git-based npm install (cross-platform)

This verifies that `npm install git+https://...` works on all platforms,
which triggers the prepare script and requires bun to be available.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: ochafik

.github/workflows/ci.yml

@@ -57,3 +57,39 @@ jobs:
       - run: npm test
 
       - run: npm run prettier
+
+  # Test that the package can be installed from git (triggers prepare script)
+  test-git-install:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            name: Linux x64
+          - os: windows-latest
+            name: Windows x64
+          - os: macos-latest
+            name: macOS ARM64
+
+    name: Test git install (${{ matrix.name }})
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: latest
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "20"
+
+      - name: Create test project and install from git
+        shell: bash
+        run: |
+          mkdir test-project
+          cd test-project
+          npm init -y
+          # Install from the PR branch
+          npm install "git+https://github.com/${{ github.repository }}#${{ github.head_ref || github.ref_name }}"
+          # Verify the package is usable (ESM import)
+          node --input-type=module -e "import { App } from '@modelcontextprotocol/ext-apps'; console.log('Import successful:', typeof App)"