Fix test suite teardown and gate CI on tests plus header WCAG audit.

Repair Navigation and HeroSection assertions, stop deleting window.location in jsdom setup, and add validate/a11y-live GitHub workflows with type-check and test:ci scripts.

Co-authored-by: Cursor <[email protected]>

.github/workflows/a11y-live.yml

@@ -0,0 +1,43 @@
+name: Live header accessibility audit
+
+# Post-deploy / scheduled Lighthouse on production mim4u.org (requires Chrome).
+on:
+  schedule:
+    - cron: '0 14 * * 1'
+  workflow_dispatch:
+
+jobs:
+  lighthouse-a11y:
+    name: Lighthouse + WCAG header audit (live)
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '22'
+
+      - name: Setup Chrome
+        uses: browser-actions/setup-chrome@v1
+        id: setup-chrome
+
+      - name: Run live header accessibility audit
+        run: |
+          export CHROME_PATH="${{ steps.setup-chrome.outputs.chrome-path }}"
+          if [[ -z "$CHROME_PATH" ]]; then
+            CHROME_PATH="$(command -v google-chrome || command -v chromium-browser)"
+          fi
+          export CHROME_PATH
+          npm run a11y:header-audit:live
+
+      - name: Upload audit reports
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: mim4u-a11y-reports
+          path: |
+            reports/status/mim4u-header-wcag-audit-latest.json
+            reports/status/lighthouse-a11y-mim4u-latest.json
+          if-no-files-found: warn