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/plugins/templates/models/model.py.tmpl

@@ -0,0 +1,32 @@
+"""$Name model.
+
+This is an Asset extension table keyed by assetid. The Asset row holds
+the platform fields (assetnumber, name, vendorid, locationid, etc.);
+this table holds the $name-specific fields. Replace the example fields
+below with your domain model.
+"""
+
+from shopdb.api import db, BaseModel
+
+
+class $Name(BaseModel):
+    """$Name domain entity, extending Asset by assetid."""
+
+    __tablename__ = '$name'
+
+    assetid = db.Column(
+        db.Integer,
+        db.ForeignKey('assets.assetid', ondelete='CASCADE'),
+        primary_key=True,
+    )
+
+    # TODO: replace these example fields with your domain fields.
+    examplefield = db.Column(db.String(255), nullable=True)
+
+    asset = db.relationship('Asset', backref=db.backref('$name', uselist=False))
+
+    def to_dict(self):
+        return {
+            'assetid': self.assetid,
+            'examplefield': self.examplefield,
+        }