Fix Pages deploy workflow for transient backend failures.

Disable cancel-in-progress, add retry with backoff, and increase deploy-pages polling limits.

Author: krwg

.github/workflows/pages.yml

@@ -12,7 +12,7 @@ permissions:
 
 concurrency:
   group: pages
-  cancel-in-progress: true
+  cancel-in-progress: false
 
 jobs:
   build:
@@ -21,8 +21,6 @@ jobs:
       - uses: actions/checkout@v4
 
       - uses: actions/configure-pages@v5
-        with:
-          enablement: true
 
       - name: Validate site
         run: test -f docs/index.html
@@ -36,7 +34,30 @@ jobs:
     runs-on: ubuntu-latest
     environment:
       name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}
+      url: ${{ steps.deployment-retry.outputs.page_url || steps.deployment.outputs.page_url }}
     steps:
-      - uses: actions/deploy-pages@v4
+      - name: Deploy to GitHub Pages
         id: deployment
+        uses: actions/deploy-pages@v4
+        continue-on-error: true
+        with:
+          timeout: 900000
+          error_count: 15
+          reporting_interval: 10000
+
+      - name: Wait before retry
+        if: steps.deployment.outcome == 'failure'
+        run: sleep 60
+
+      - name: Retry deploy (transient Pages failures)
+        id: deployment-retry
+        if: steps.deployment.outcome == 'failure'
+        uses: actions/deploy-pages@v4
+        with:
+          timeout: 900000
+          error_count: 15
+          reporting_interval: 10000
+
+      - name: Fail if both deploy attempts failed
+        if: steps.deployment.outcome == 'failure' && steps.deployment-retry.outcome == 'failure'
+        run: exit 1