fix(config): agrega roles Taller y Mecanico en creacion de empleados

- Agrega opciones workshop y mechanic al select de rol en config.html
- Actualiza ROLE_LABELS y ROLE_BADGE en config.js
- Valida roles mechanic y workshop en config_bp.py con permisos por defecto
- Añade clases CSS badge--orange y badge--teal

Tests: 35 passed

pos/blueprints/config_bp.py

@@ -200,7 +200,7 @@ def create_employee():
         nxt_name = PLANS[nxt]['name'] if nxt else 'Enterprise'
         return jsonify({'error': f'Plan limit reached ({limit} employees). Upgrade to {nxt_name}.'}), 403
 
-    valid_roles = ['admin', 'cashier', 'warehouse', 'accountant', 'workshop']
+    valid_roles = ['admin', 'cashier', 'warehouse', 'accountant', 'workshop', 'mechanic']
     if data['role'] not in valid_roles:
         return jsonify({'error': f'role must be one of: {", ".join(valid_roles)}'}), 400
 
@@ -239,6 +239,8 @@ def create_employee():
                         'fleet.view'],
         'workshop': ['workshop.view', 'workshop.edit', 'workshop.add_items', 'customers.view',
                      'fleet.view'],
+        'mechanic': ['workshop.view', 'workshop.edit', 'workshop.add_items', 'customers.view',
+                     'fleet.view'],
     }
 
     for perm in role_permissions.get(data['role'], []):