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

shopdb/core/models/dashboarddefault.py

@@ -0,0 +1,28 @@
+"""Dashboard default model: visitor-IP -> business-unit mapping.
+
+A shopfloor / lobby kiosk display resolves which business unit to show by the
+display PC's IP address. Powers the visitor-location lookup the shopfloor and
+TV dashboards call when no explicit business unit is given.
+"""
+
+from shopdb.extensions import db
+from .base import BaseModel
+
+
+class DashboardDefault(BaseModel):
+    """Maps a display PC IP address to the business unit it should show."""
+    __tablename__ = 'dashboarddefaults'
+
+    dashboarddefaultid = db.Column(db.Integer, primary_key=True)
+    ipaddress = db.Column(db.String(50), unique=True, nullable=False)
+    businessunitid = db.Column(
+        db.Integer,
+        db.ForeignKey('businessunits.businessunitid'),
+        nullable=False
+    )
+    description = db.Column(db.String(255))
+
+    businessunit = db.relationship('BusinessUnit')
+
+    def __repr__(self):
+        return f"<DashboardDefault {self.ipaddress} -> {self.businessunitid}>"