feat: implement customizable funnel stages per tenant

- Modified attendances.funnel_stage in DB from ENUM to VARCHAR.

- Created tenant_funnels table and backend API routes to manage custom stages.

- Added /admin/funnels page for Admins/Managers to create, edit, order, and color-code their funnel stages.

- Updated Dashboard, UserDetail, and AttendanceDetail to fetch and render dynamic funnel stages instead of hardcoded enums.

- Added defensive checks and logging to GET /users/:idOrSlug to fix sporadic 500 errors during impersonation handoffs.

components/Layout.tsx

@@ -2,7 +2,7 @@ import React, { useState, useEffect } from 'react';
 import { NavLink, useLocation, useNavigate } from 'react-router-dom';
 import { 
   LayoutDashboard, Users, UserCircle, Bell, Search, Menu, X, LogOut, 
-  Hexagon, Settings, Building2, Sun, Moon, Loader2 
+  Hexagon, Settings, Building2, Sun, Moon, Loader2, Layers 
 } from 'lucide-react';
 import { 
   getAttendances, getUsers, getUserById, logout, searchGlobal, 
@@ -194,6 +194,7 @@ export const Layout: React.FC<{ children: React.ReactNode }> = ({ children }) =>
                   <>
                     <SidebarItem to="/admin/users" icon={Users} label="Membros" collapsed={false} />
                     <SidebarItem to="/admin/teams" icon={Building2} label={currentUser.role === 'manager' ? 'Meu Time' : 'Times'} collapsed={false} />
+                    <SidebarItem to="/admin/funnels" icon={Layers} label="Meus Funis" collapsed={false} />
                   </>
                 )}
               </>