Migrate frontend to plugin-based asset architecture

- Add equipmentApi and computersApi to replace legacy machinesApi
- Add controller vendor/model fields to Equipment model and forms
- Fix map marker navigation to use plugin-specific IDs (equipmentid,
  computerid, printerid, networkdeviceid) instead of assetid
- Fix search to use unified Asset table with correct plugin IDs
- Remove legacy printer search that used non-existent field names
- Enable optional JWT auth for detail endpoints (public read access)
- Clean up USB plugin models (remove unused checkout model)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/usb/models/__init__.py

@@ -1,5 +1,5 @@
 """USB plugin models."""
 
-from .usb_checkout import USBCheckout
+from .usb_device import USBDevice, USBDeviceType, USBCheckout
 
-__all__ = ['USBCheckout']
+__all__ = ['USBDevice', 'USBDeviceType', 'USBCheckout']