eat: implement Holesail-Browser enhancement plan

- Add unit tests (hostname-validator, TLDs, payload-schemas) and integration tests for message handler registry
- Refactor native host message router into handler registry (handlers/state, tunnels, ssh, rdp, backup, ca, connections)
- Add ESLint config and npm test + lint steps in CI
- Dashboard: visibility-based refresh pause, configurable refresh interval (2s/5s/10s/paused)
- Accessibility: ARIA on nav and modals, focus trap and restore, prefers-reduced-motion
- Empty states: primary action buttons for virtual hosts, servers, service tunnels
- Native host rate limiting for backup and CA operations; update SECURITY.md
- CONTRIBUTING: "Adding a new dashboard page", dev workflow; add npm run dev script

extension/dashboard/pages/virtual-hosts.js

@@ -44,7 +44,8 @@ function updateConnectionsTable(state) {
         <div class="empty-state">
           <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.5"><circle cx="12" cy="12" r="2"/><circle cx="4" cy="6" r="2"/><circle cx="20" cy="6" r="2"/><circle cx="4" cy="18" r="2"/><circle cx="20" cy="18" r="2"/><line x1="6" y1="6" x2="10" y2="11"/><line x1="18" y1="6" x2="14" y2="11"/><line x1="6" y1="18" x2="10" y2="13"/><line x1="18" y1="18" x2="14" y2="13"/></svg>
           <div class="empty-state-title">No virtual hosts</div>
-          <div class="empty-state-desc">Click "Add Host" to assign a hostname to an hs:// tunnel</div>
+          <div class="empty-state-desc">Assign a hostname to an hs:// tunnel to browse it in your browser.</div>
+          <button type="button" class="btn btn-primary empty-state-btn" data-open-modal="modal-addVhost">Add your first virtual host</button>
         </div>
       </td></tr>`;
     _updateVhostBulkBar();