chore: preview branch output inside description instead of comment

.github/workflows/03-preview-url-pr-description.yml

@@ -0,0 +1,21 @@
+name: Preview URL PR Description
+
+permissions:
+  pull-requests: write
+
+on:
+  workflow_call:
+
+jobs:
+  preview-url-pr-description:
+    runs-on: ubuntu-24.04 # Use Ubuntu 24.04 explicitly
+    steps:
+      - name: ⏬ Checkout repo
+        uses: actions/checkout@v5
+
+      - name: 🔭 Add url for preview page
+        uses: actions/github-script@v8
+        with:
+          script: |
+            const { default: previewUrlPrDescription } = await import('${{ github.workspace }}/scripts/github/preview-url-pr-description.js');
+            return await previewUrlPrDescription({github, context});

.github/workflows/default.yml

@@ -394,3 +394,8 @@ jobs:
     with:
       release: false
       preRelease: false
+
+  preview-url-pr-description:
+    if: ${{ !cancelled() && github.event.pull_request != null }}
+    needs: [deploy]
+    uses: ./.github/workflows/03-preview-url-pr-description.yml

scripts/github/preview-url-pr-description.js

@@ -0,0 +1,43 @@
+/* eslint-disable camelcase */
+// Usage: node update-pr-description.js <owner> <repo> <pull_number> <head_ref>
+// Requires: GITHUB_TOKEN in env
+
+/**
+ * Update PR description with a test URL section.
+ * @param {import('@actions/github').GitHub} github - Octokit client from actions/github-script
+ * @param {object} context - GitHub Actions context
+ */
+async function previewUrlPrDescription({ github, context }) {
+	const { owner, repo } = context.repo;
+	const pullNumber = context.payload.pull_request.number;
+	const headRef = context.payload.pull_request.head.ref;
+
+	// Fetch current PR
+	const pr = await github.rest.pulls.get({
+		owner,
+		repo,
+		pull_number: pullNumber
+	});
+	const urlSectionStart = '\n<!-- DBUX-TEST-URL-START -->';
+	const urlSectionEnd = '\n<!-- DBUX-TEST-URL-END -->';
+	const testUrl = `🔭🐙🐈 Test this branch here: https://${owner}.github.io/${repo}/review/${headRef}`;
+	let body = pr.data.body || '';
+	// Remove any existing test URL section
+	const startIdx = body.indexOf(urlSectionStart);
+	const endIdx = body.indexOf(urlSectionEnd);
+	if (startIdx !== -1 && endIdx !== -1 && endIdx > startIdx) {
+		body =
+			body.slice(0, startIdx) + body.slice(endIdx + urlSectionEnd.length);
+	}
+
+	// Add the new test URL section at the end
+	body = body.trim() + `${urlSectionStart}\n${testUrl}${urlSectionEnd}`;
+	await github.rest.pulls.update({
+		owner,
+		repo,
+		pull_number: pullNumber,
+		body
+	});
+}
+
+export default previewUrlPrDescription;