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>

migrations/env.py

@@ -4,6 +4,27 @@ from logging.config import fileConfig
 from flask import current_app
 
 from alembic import context
+from sqlalchemy.ext.compiler import compiles
+from sqlalchemy.schema import CreateTable
+
+
+# Force every table the migrations create on MySQL to utf8mb4 + DYNAMIC row
+# format. Without this a fresh `flask db upgrade` inherits the server default
+# charset, so a box whose default is latin1 (common on older MySQL) silently
+# builds a latin1 schema that drifts from the utf8mb4 production target. The
+# DYNAMIC row format also keeps utf8mb4 indexes under the 767-byte prefix limit
+# on pre-5.7 InnoDB. Scoped to the mysql dialect so the SQLite test DB is
+# untouched.
+@compiles(CreateTable, "mysql")
+def _mysql_create_table_utf8mb4(element, compiler, **kw):
+    sql = compiler.visit_create_table(element, **kw)
+    if "CHARSET" not in sql.upper():
+        sql = sql.rstrip().rstrip(";")
+        sql += (
+            " ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"
+            " COLLATE=utf8mb4_unicode_ci ROW_FORMAT=DYNAMIC"
+        )
+    return sql
 
 # this is the Alembic Config object, which provides
 # access to the values within the .ini file in use.