test: add integration test workflow for VS Code workflows

Tests the complete VS Code CI infrastructure:
- Package workflow (VSIX creation)
- Composite actions (npm-install, detect-packages, calculate-artifact-name)
- CLI scripts (ext-package-selector, ext-build-type)

Run manually from Actions tab with workflow_dispatch.

Author: madhur310

.github/workflows/test-vscode-workflows-integration.yml

@@ -0,0 +1,169 @@
+name: Test VS Code Workflows Integration
+
+on:
+  workflow_dispatch:
+    inputs:
+      test-repo:
+        description: 'Repository to test with'
+        required: false
+        default: 'apex-language-support'
+        type: choice
+        options:
+          - apex-language-support
+          - salesforcedx-vscode
+
+jobs:
+  test-package-workflow:
+    name: Test Package Workflow
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout apex-language-support
+        uses: actions/checkout@v6
+        with:
+          repository: forcedotcom/apex-language-support
+          path: test-repo
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: '22.x'
+
+      - name: Install dependencies
+        working-directory: test-repo
+        run: npm ci
+
+      - name: Build and package extension
+        working-directory: test-repo/packages/apex-lsp-vscode-extension
+        run: |
+          npm run vscode:package
+          ls -la *.vsix
+          echo "✓ VSIX packaging successful"
+
+  test-composite-actions:
+    name: Test Composite Actions
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout github-workflows
+        uses: actions/checkout@v6
+        path: toolkit
+
+      - name: Checkout apex-language-support
+        uses: actions/checkout@v6
+        with:
+          repository: forcedotcom/apex-language-support
+          path: test-repo
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: '22.x'
+
+      - name: Test npm-install-with-retries action
+        uses: ./toolkit/.github/actions/vscode/npm-install-with-retries
+        with:
+          working-directory: test-repo
+
+      - name: Test detect-packages action
+        id: detect
+        uses: ./toolkit/.github/actions/vscode/detect-packages
+        with:
+          working-directory: test-repo
+
+      - name: Verify packages detected
+        run: |
+          echo "Packages: ${{ steps.detect.outputs.packages }}"
+          echo "Extensions: ${{ steps.detect.outputs.extensions }}"
+          if [ -z "${{ steps.detect.outputs.extensions }}" ]; then
+            echo "Error: No extensions detected"
+            exit 1
+          fi
+          echo "✓ Package detection successful"
+
+      - name: Test calculate-artifact-name action
+        id: artifact
+        uses: ./toolkit/.github/actions/vscode/calculate-artifact-name
+        with:
+          extension-name: apex-lsp-vscode-extension
+          mode: nightly
+
+      - name: Verify artifact name
+        run: |
+          echo "Artifact: ${{ steps.artifact.outputs.artifact-name }}"
+          if [ -z "${{ steps.artifact.outputs.artifact-name }}" ]; then
+            echo "Error: No artifact name generated"
+            exit 1
+          fi
+          echo "✓ Artifact naming successful"
+
+  test-scripts:
+    name: Test CLI Scripts
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout github-workflows
+        uses: actions/checkout@v6
+        path: toolkit
+
+      - name: Checkout apex-language-support
+        uses: actions/checkout@v6
+        with:
+          repository: forcedotcom/apex-language-support
+          path: test-repo
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v6
+        with:
+          node-version: '22.x'
+
+      - name: Build vscode-extension-ci package
+        working-directory: toolkit/packages/vscode-extension-ci
+        run: |
+          npm install
+          npm run build
+
+      - name: Test ext-package-selector
+        working-directory: test-repo
+        run: |
+          node ../toolkit/packages/vscode-extension-ci/dist/cli.js ext-package-selector
+          echo "✓ Package selector works"
+
+      - name: Test ext-build-type
+        working-directory: test-repo
+        run: |
+          node ../toolkit/packages/vscode-extension-ci/dist/cli.js ext-build-type
+          echo "✓ Build type detection works"
+
+  summary:
+    name: Test Summary
+    runs-on: ubuntu-latest
+    needs: [test-package-workflow, test-composite-actions, test-scripts]
+    if: always()
+    steps:
+      - name: Check results
+        env:
+          PACKAGE_RESULT: ${{ needs.test-package-workflow.result }}
+          ACTIONS_RESULT: ${{ needs.test-composite-actions.result }}
+          SCRIPTS_RESULT: ${{ needs.test-scripts.result }}
+        run: |
+          echo "Package Workflow: $PACKAGE_RESULT"
+          echo "Composite Actions: $ACTIONS_RESULT"
+          echo "CLI Scripts: $SCRIPTS_RESULT"
+
+          FAILED=0
+          if [ "$PACKAGE_RESULT" != "success" ]; then
+            echo "❌ Package workflow failed"
+            FAILED=1
+          fi
+          if [ "$ACTIONS_RESULT" != "success" ]; then
+            echo "❌ Composite actions failed"
+            FAILED=1
+          fi
+          if [ "$SCRIPTS_RESULT" != "success" ]; then
+            echo "❌ CLI scripts failed"
+            FAILED=1
+          fi
+
+          if [ $FAILED -eq 0 ]; then
+            echo "✅ All integration tests passed!"
+          else
+            exit 1
+          fi