ci: deploy docs via GitHub Actions to py.sdk.modelcontextprotocol.io

Replace the manual gh-deploy workflow with the GitHub Actions Pages
artifact pipeline (configure-pages -> upload-pages-artifact ->
deploy-pages) and deploy on push to main.

The previous workflow pushed the built site to the gh-pages branch with
mkdocs gh-deploy --force. With branch-based Pages, a custom domain only
works via a CNAME file in the branch, which a force-push overwrites on
every publish. Switching to artifact-based deployment lets the custom
domain live as a persistent repository Pages setting instead, so it
survives every deploy, and drops the contents: write permission in
favour of the scoped pages/id-token tokens.

Also point site_url at https://py.sdk.modelcontextprotocol.io/ so
canonical links and the sitemap match the SDK's published domain.

Closes #2614.

Author: maxisbey

.github/workflows/deploy-docs.yml

@@ -0,0 +1,60 @@
+name: Deploy Docs
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+concurrency:
+  group: deploy-docs
+  cancel-in-progress: true
+
+jobs:
+  deploy-docs:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      pages: write
+      id-token: write
+
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
+
+      - name: Install uv
+        uses: astral-sh/setup-uv@803947b9bd8e9f986429fa0c5a41c367cd732b41 # v7.2.1
+        with:
+          enable-cache: true
+          version: 0.9.5
+
+      - run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV
+      - uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        with:
+          key: mkdocs-material-${{ env.cache_id }}
+          path: .cache
+          restore-keys: |
+            mkdocs-material-
+
+      - run: uv sync --frozen --group docs
+
+      - name: Build docs
+        run: uv run --frozen --no-sync mkdocs build
+        env:
+          ENABLE_SOCIAL_CARDS: "true"
+
+      - name: Configure Pages
+        uses: actions/configure-pages@45bfe0192ca1faeb007ade9deae92b16b8254a0d # v6.0.0
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@fc324d3547104276b827a68afc52ff2a11cc49c9 # v5.0.0
+        with:
+          path: site
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@cd2ce8fcbc39b97be8ca5fce6e763baed58fa128 # v5.0.0

.github/workflows/publish-docs-manually.yml

@@ -5,7 +5,7 @@ strict: true
 repo_name: modelcontextprotocol/python-sdk
 repo_url: https://github.com/modelcontextprotocol/python-sdk
 edit_uri: edit/main/docs/
-site_url: https://modelcontextprotocol.github.io/python-sdk
+site_url: https://py.sdk.modelcontextprotocol.io/
 
 # TODO(Marcelo): Add Anthropic copyright?
 # copyright: © Model Context Protocol 2025 to present