Add custom fields + warranty plugin, rework settings into two-pane shell

Feature work from the 2026-07 session:

Settings IA
- Replace the flat 27-card settings hub with a persistent two-pane shell
  (SettingsLayout.vue): grouped, searchable left rail + content pane.
- Nest all settings/* routes under the shell via router post-processing;
  shared nav catalog in settingsNav.js. Group by asset class (PCs, Printers,
  Equipment, Network) so per-type settings stop scattering.

Custom fields (core)
- customfields + customfieldvalues tables (migration 7d14), CRUD API at
  /api/customfields, per-asset value get/save.
- Settings management page + reusable CustomFieldsSection (detail) and
  CustomFieldsInputs (form) wired into all four asset types.

Warranty (new plugin)
- plugins/warranty: warranties + warrantyassets (migration 7d15), derived
  coverage status, provider abstraction (manual now; Dell/Lenovo/HP stubs).
- API CRUD + per-asset panel + report buckets; WarrantyPanel on all four
  detail pages; Warranties management page; Warranty report + Reports card.
- Seed warranty.* permissions.

Printer drivers
- printerdrivers table (migration 7d13) linked to printer models; drivers now
  surface on the matching printer's detail page.

Other
- PCDetail rebalanced (Network + Status + Warranty + custom fields on the right).
- Rename PCs list "Features" column to "Remote Access"; fix badge hover underline.
- Drop equipment islocationonly field.
- Centralize asset-type label/route maps into utils/assetTypes.js.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

shopdb/core/api/models.py

@@ -13,6 +13,8 @@ from shopdb.utils.responses import (
 )
 from shopdb.utils.pagination import get_pagination_params, paginate_query
 
+from shopdb.utils.authz import require_permission, require_role
+
 models_bp = Blueprint('models', __name__)
 
 
@@ -72,6 +74,7 @@ def get_model(model_id: int):
 
 @models_bp.route('', methods=['POST'])
 @jwt_required()
+@require_role('admin')
 def create_model():
     """Create a new model."""
     data = request.get_json()
@@ -109,6 +112,7 @@ def create_model():
 
 @models_bp.route('/<int:model_id>', methods=['PUT'])
 @jwt_required()
+@require_role('admin')
 def update_model(model_id: int):
     """Update a model."""
     m = Model.query.get(model_id)
@@ -134,6 +138,7 @@ def update_model(model_id: int):
 
 @models_bp.route('/<int:model_id>', methods=['DELETE'])
 @jwt_required()
+@require_role('admin')
 def delete_model(model_id: int):
     """Delete (deactivate) a model."""
     m = Model.query.get(model_id)