Zabbix supply backend rebuild + data-driven model supplies

Rewrite the printer Zabbix integration (Bearer auth, host-by-IP, tag-based
supply lookup, ping) and replace the hardcoded toner table with a
modelsupplies table + CRUD + seed. Add mock Zabbix server, live test
harness, and the Playwright screenshot tooling.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

plugins/printers/services/__init__.py

@@ -1,5 +1,19 @@
 """Printers plugin services."""
 
 from .zabbix_service import ZabbixService
+from .supply_parts import (
+    classifysupply,
+    derivesupplytype,
+    derivecolor,
+    lookupsupplies,
+)
+from .seed_supplies import seedsupplies
 
-__all__ = ['ZabbixService']
+__all__ = [
+    'ZabbixService',
+    'classifysupply',
+    'derivesupplytype',
+    'derivecolor',
+    'lookupsupplies',
+    'seedsupplies',
+]