Add technician login and dashboard pages

- Add /login page with dark theme matching portal
- Add /dashboard with 4 tabs: Support, Access, Build, Settings
- Add clean URL routes (/login, /dashboard) to server
- Add "Technician Login" link to portal footer
- Dashboard shows active support codes with generate/cancel
- Build tab has installer builder form (placeholder for agent)
- Access tab has 3-panel layout for machine management

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server/static/index.html

@@ -254,6 +254,7 @@
 
         <div class="footer">
             <p>Need help? Contact <a href="mailto:support@azcomputerguru.com">support@azcomputerguru.com</a></p>
+            <p style="margin-top: 12px;"><a href="/login" style="color: hsl(var(--muted-foreground)); font-size: 11px;">Technician Login</a></p>
         </div>
     </div>