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

requirements.in

@@ -0,0 +1,32 @@
+# Flask and extensions
+flask>=3.0
+flask-sqlalchemy>=3.1
+flask-migrate>=4.0
+flask-jwt-extended>=4.6
+flask-cors>=4.0
+flask-caching>=2.0
+flask-marshmallow>=1.2
+marshmallow-sqlalchemy>=0.29
+
+# Database
+mysql-connector-python>=8.0
+pymysql>=1.1
+
+# CLI and utilities
+click>=8.1
+python-dotenv>=1.0
+tabulate>=0.9
+
+# HTTP/API clients
+requests>=2.31
+
+# Security
+werkzeug>=3.0
+
+# Validation
+email-validator>=2.0
+
+# Testing
+pytest>=7.0
+pytest-flask>=1.2
+pytest-cov>=4.0