Initial import: shopdb-flask multi-site asset platform

Flask + Vue rewrite of the classic-ASP shopdb, built as a plugin
framework so sister GE Aerospace sites can adopt it. Product version
0.7.0-pre-0.8.0, plugin contract 0.11.0, 966 backend tests.

Key entry points:
- docs/INSTALL-WINDOWS-IIS.md - tested Windows + IIS install runbook
  (own-site and subpath deployment methods)
- docs/PILOT-DEPLOY.md - production pilot: stand up + import + verify
- docs/IMPORT-API.md - schema-agnostic legacy data import contract
- scripts/site_imports/wjf/ - West Jefferson reference import loader
- docs/adr/ - twelve accepted architecture decision records

plugins/printers/models/__init__.py

@@ -0,0 +1,20 @@
+"""Printers plugin models."""
+
+from .printer import Printer, PrinterType  # Asset-based models
+from .printer_driver import PrinterDriver
+from .model_supply import (  # data-driven model -> toner/drum/waste mapping
+    ModelSupply,
+    SUPPLY_TYPES,
+    SUPPLY_COLORS,
+    CAPACITY_TIERS,
+)
+
+__all__ = [
+    'Printer',
+    'PrinterType',
+    'PrinterDriver',
+    'ModelSupply',
+    'SUPPLY_TYPES',
+    'SUPPLY_COLORS',
+    'CAPACITY_TIERS',
+]