feat: Add Team-Members management page

- New /team route to view all team members
- Add/activate/deactivate team members via UI
- Display name, role, email, responsibilities, telegram_id
- Integrated into main navigation
- Self-learning system info displayed

templates/base.html

@@ -64,6 +64,11 @@
               <span>📋</span> Log
             </a>
           </li>
+          <li class="nav-item">
+            <a class="nav-link {% if request.path == '/team' %}active{% endif %}" href="/team">
+              <span>👥</span> Team
+            </a>
+          </li>
           <li class="nav-item">
             <a class="nav-link {% if request.path == '/settings' %}active{% endif %}" href="/settings">
               <span>⚙</span> Settings