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/api/__init__.py

@@ -42,6 +42,8 @@ from shopdb.core.models import (
     Application,
     AppVersion,
     OperatingSystem,
+    AssetRelationship,
+    RelationshipType,
 )
 
 # Response + pagination helpers for plugin API blueprints
@@ -53,9 +55,15 @@ from shopdb.utils.responses import (
 )
 from shopdb.utils.pagination import get_pagination_params, paginate_query
 
+# Authorization decorators for gating plugin write routes
+from shopdb.utils.authz import require_permission, require_role
+
 # Legacy employee directory lookup (read-only) used by notifications
 from shopdb.utils.employee_db import employee_connection
 
+# CMMC USB check-in/out database (read-write) used by the usb plugin
+from shopdb.utils.cmmc_usb_db import cmmc_usb_connection
+
 
 def audit_log(
     action: str,
@@ -219,6 +227,8 @@ __all__ = [
     'Application',
     'AppVersion',
     'OperatingSystem',
+    'AssetRelationship',
+    'RelationshipType',
     # Response + pagination helpers
     'success_response',
     'error_response',
@@ -226,6 +236,11 @@ __all__ = [
     'ErrorCodes',
     'get_pagination_params',
     'paginate_query',
+    # Authorization decorators
+    'require_permission',
+    'require_role',
     # Legacy employee directory
     'employee_connection',
+    # CMMC USB check-in/out database
+    'cmmc_usb_connection',
 ]