Fix linkcheck false positives for FRED (timeout) and update redirect URLs

.github/workflows/linkcheck.yml

@@ -24,6 +24,31 @@ jobs:
         run: |
           mkdir -p _site
           curl -sL "${{ steps.release.outputs.asset-url }}" | tar -xz -C _site
+      - name: Pre-process HTML to exclude known bot-blocking domains
+        env:
+          # Domains that block automated crawlers (space-separated).
+          # These are also listed in linkcheck_ignore in lectures/_config.yml.
+          SKIP_DOMAINS: "fred.stlouisfed.org"
+        run: |
+          python3 - <<'PYEOF'
+          import os
+          import re
+          from pathlib import Path
+          skip_domains = os.environ.get('SKIP_DOMAINS', '').split()
+          count = 0
+          for html_file in Path('_site').rglob('*.html'):
+              try:
+                  content = html_file.read_text(encoding='utf-8')
+              except UnicodeDecodeError as exc:
+                  print(f"Skipping {html_file}: encoding error - {exc}")
+                  continue
+              for domain in skip_domains:
+                  pattern = r'href="https?://' + re.escape(domain) + r'[^"]*"'
+                  content = re.sub(pattern, 'href="#"', content)
+              html_file.write_text(content, encoding='utf-8')
+              count += 1
+          print(f"Pre-processing complete ({count} files processed)")
+          PYEOF
       - name: AI-Powered Link Checker
         uses: QuantEcon/action-link-checker@main
         with: