ci: add Cloudflare Pages preview for docs PRs

Deploys a per-PR preview of the TypeDoc site to Cloudflare Pages project
mcp-ext-apps-docs-preview when docs, src JSDoc, README, or typedoc config
change. Uses the shared modelcontextprotocol/actions composite action that
injects noindex headers, posts a sticky PR comment with preview URLs, and
cleans up deployments on PR close. Fork PRs are skipped (no secret access).

Author: localden

.github/workflows/docs-preview.yml

@@ -0,0 +1,65 @@
+name: Docs Preview
+
+on:
+  pull_request:
+    types: [opened, synchronize, reopened, closed]
+    paths:
+      - "docs/**"
+      - "src/**"
+      - "README.md"
+      - "typedoc.config.mjs"
+      - "scripts/typedoc-*.mjs"
+      - ".github/workflows/docs-preview.yml"
+
+permissions:
+  contents: read
+  pull-requests: write
+
+concurrency:
+  group: docs-preview-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  build-and-deploy:
+    # Refuse to run for fork PRs — forks do not have access to the Cloudflare
+    # secrets, so deploys would fail anyway.
+    if: >-
+      github.event.action != 'closed' &&
+      github.event.pull_request.head.repo.full_name == github.repository
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - uses: actions/setup-node@v6
+        with:
+          node-version: "22"
+          cache: npm
+
+      - run: npm ci
+
+      - run: npm run build
+
+      - run: npm run docs
+
+      - name: Deploy preview
+        uses: modelcontextprotocol/actions/cloudflare-pages-preview/deploy@main
+        with:
+          directory: docs
+          project-name: mcp-ext-apps-docs-preview
+          api-token: ${{ secrets.CF_PAGES_PREVIEW_API_TOKEN }}
+          account-id: ${{ secrets.CF_PAGES_PREVIEW_ACCOUNT_ID }}
+          comment-title: "📖 Docs Preview Deployed"
+          comment-marker: "<!-- docs-preview-comment -->"
+
+  cleanup:
+    if: >-
+      github.event.action == 'closed' &&
+      github.event.pull_request.head.repo.full_name == github.repository
+    runs-on: ubuntu-latest
+    steps:
+      - uses: modelcontextprotocol/actions/cloudflare-pages-preview/cleanup@main
+        with:
+          project-name: mcp-ext-apps-docs-preview
+          api-token: ${{ secrets.CF_PAGES_PREVIEW_API_TOKEN }}
+          account-id: ${{ secrets.CF_PAGES_PREVIEW_ACCOUNT_ID }}
+          comment-marker: "<!-- docs-preview-comment -->"