feat: add getUserById endpoint for admin user details

Added GET /api/admin/users/:id endpoint to retrieve detailed user
information including contact info, personal data, and ticket statistics.
This enables the admin interface to display comprehensive user details
when clicking the "Détails" button.

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

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

src/controllers/admin.controller.js

@@ -450,6 +450,48 @@ export const createEmployee = asyncHandler(async (req, res, next) => {
   });
 });
 
+/**
+ * Récupérer un utilisateur par ID
+ * GET /api/admin/users/:id
+ */
+export const getUserById = asyncHandler(async (req, res, next) => {
+  const { id } = req.params;
+
+  const result = await pool.query(
+    `SELECT
+      u.id,
+      u.email,
+      u.first_name,
+      u.last_name,
+      u.phone,
+      u.address,
+      u.city,
+      u.postal_code,
+      u.role,
+      u.is_verified,
+      u.created_at,
+      u.date_of_birth,
+      u.gender,
+      COUNT(t.id) as tickets_count,
+      COUNT(CASE WHEN t.status = 'PENDING' THEN 1 END) as pending_tickets,
+      COUNT(CASE WHEN t.status = 'CLAIMED' THEN 1 END) as claimed_tickets
+    FROM users u
+    LEFT JOIN tickets t ON u.id = t.user_id
+    WHERE u.id = $1
+    GROUP BY u.id`,
+    [id]
+  );
+
+  if (result.rows.length === 0) {
+    return next(new AppError('Utilisateur non trouvé', 404));
+  }
+
+  res.json({
+    success: true,
+    data: result.rows[0],
+  });
+});
+
 /**
  * Mettre à jour un utilisateur
  * PUT /api/admin/users/:id
@@ -812,6 +854,7 @@ export default {
   updatePrize,
   deletePrize,
   getAllUsers,
+  getUserById,
   createEmployee,
   updateUser,
   deleteUser,

src/routes/admin.routes.js

@@ -32,6 +32,7 @@ router.delete('/prizes/:id', validate(deletePrizeSchema), adminController.delete
 
 // Gestion des utilisateurs
 router.get('/users', validate(paginationSchema), adminController.getAllUsers);
+router.get('/users/:id', adminController.getUserById);
 router.post('/employees', validate(createEmployeeSchema), adminController.createEmployee);
 router.put('/users/:id', validate(updateUserSchema), adminController.updateUser);
 router.delete('/users/:id', adminController.deleteUser);