refactor(ci): harmonize sticky PR comment lifecycle

.github/workflows/_ci.yml

@@ -15,6 +15,44 @@ jobs:
       pull-requests: write
     runs-on: ubuntu-latest
     steps:
+      - name: Mark lint run in progress
+        if: >-
+          github.event_name == 'pull_request' &&
+          github.event.pull_request.head.repo.full_name == github.repository
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
+        with:
+          script: |
+            const marker = '<!-- shared-workflows-ci-status -->';
+            const workflowUrl = `${context.serverUrl}/${context.repo.owner}/${context.repo.repo}/actions/runs/${context.runId}`;
+            const { data: comments } = await github.rest.issues.listComments({ owner: context.repo.owner, repo: context.repo.repo, issue_number: context.issue.number });
+            const existing = comments.find((comment) => comment.body?.includes(marker));
+            let previous = '';
+            if (existing) {
+              if (existing.body.includes('this comment will be updated when the run completes')) {
+                const match = existing.body.match(/<details><summary>Previous run output<\/summary>\n\n([\s\S]*)\n\n<\/details>\s*$/);
+                previous = match ? match[1].trim() : '';
+              } else {
+                previous = existing.body.replace(marker, '').trim();
+              }
+            }
+            const parts = [
+              marker,
+              '#### Shared Workflows CI',
+              '',
+              'Shared workflows CI is in progress; this comment will be updated when the run completes.',
+              '',
+              `[View the workflow run](${workflowUrl}).`,
+            ];
+            if (previous) {
+              parts.push('', '<details><summary>Previous run output</summary>', '', previous, '', '</details>');
+            }
+            const body = parts.join('\n');
+            if (existing) {
+              await github.rest.issues.updateComment({ owner: context.repo.owner, repo: context.repo.repo, comment_id: existing.id, body });
+            } else {
+              await github.rest.issues.createComment({ owner: context.repo.owner, repo: context.repo.repo, issue_number: context.issue.number, body });
+            }
+
       - name: Checkout
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
@@ -47,13 +85,27 @@ jobs:
             const maxLength = 12000;
             const output = fs.existsSync('validation.log')
               ? fs.readFileSync('validation.log', 'utf8')
-                .replace(/\u001b\[[0-?]*[ -/]*[@-~]/g, '')
                 .replace(/\b(?:gh[pousr]_[A-Za-z0-9_]{20,}|github_pat_[A-Za-z0-9_]{20,})\b/g, '***REDACTED***')
                 .replace(/````/g, '\\`\\`\\`\\`')
               : 'No validation output was captured.';
             const excerpt = output.length > maxLength ? output.slice(-maxLength) : output;
             const status = failed ? 'failed' : 'passed';
-            const body = `${marker}\n## Shared workflows CI ${status}\n\n[View the workflow run](${workflowUrl}).\n\n#### Validation output (redacted, last ${maxLength} characters)\n\n\`\`\`\`text\n${excerpt}\n\`\`\`\``;
+            const body = [
+              marker,
+              '#### Shared Workflows CI',
+              '',
+              `Shared workflows CI ${status}.`,
+              '',
+              `[View the workflow run](${workflowUrl}).`,
+              '',
+              '<details><summary>View run output</summary>',
+              '',
+              '````text',
+              excerpt,
+              '````',
+              '',
+              '</details>',
+            ].join('\n');
             const { data: comments } = await github.rest.issues.listComments({
               owner: context.repo.owner,
               repo: context.repo.repo,