feat: add accessibility test suite with axe and keyboard coverage

.github/workflows/ci.yml

@@ -135,6 +135,10 @@ jobs:
           node-version: '20'
           cache: 'npm'
           cache-dependency-path: frontend/package-lock.json
+      - run: npm install
+      - run: npm test
+      - run: npm run build
+      - run: npm run lint
       - name: Install dependencies
         working-directory: ./frontend
         run: npm ci

frontend/ACCESSIBILITY_TESTING.md

@@ -0,0 +1,29 @@
+# Accessibility Testing
+
+## Running the tests
+
+```bash
+cd frontend
+npm test
+```
+
+This runs vitest in single-pass mode and prints a verbose result for every test.
+
+For watch mode during development:
+
+```bash
+npm run test:watch
+```
+
+## What is covered
+
+- `src/test/accessibility.test.tsx` — automated axe scan + keyboard behaviour for the shared `Navbar` component
+  - axe violation scan (checks roles, labels, landmark structure)
+  - keyboard Escape key does not trigger unrelated controls
+  - mobile menu toggle opens/closes correctly
+
+## Adding more tests
+
+1. Create a file under `src/test/` or co-locate as `ComponentName.a11y.test.tsx`.
+2. Import `axe` and `toHaveNoViolations` from `jest-axe`, extend `expect`, render, and call `axe(container)`.
+3. Mock `next/navigation` and any context providers the component needs (see the existing test for examples).