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/utils/cmmc_usb_db.py

@@ -0,0 +1,38 @@
+"""Connection helper for the CMMC USB check-in/out database.
+
+Credentials are pulled from app config (env-backed, see Config.CMMC_USB_DB_*),
+never hardcoded. Used by the USB plugin to track device check-in/out against a
+separate MySQL database (cmmc_usb), mirroring the read-only employee-directory
+pattern in employee_db.py. Unlike the employee DB this one is read-write, so
+callers commit their own writes and close the connection in a finally block.
+"""
+
+import pymysql
+from flask import current_app
+
+
+def _setting_or_config(setting_key, config_key):
+    """Non-secret config: a saved Setting wins, else the env-backed app config.
+
+    Lets the setup wizard edit host/name/user without touching .env, while the
+    password stays env-only.
+    """
+    from shopdb.core.models import Setting
+    try:
+        row = Setting.query.filter_by(key=setting_key).first()
+        if row and row.value:
+            return row.value
+    except Exception:
+        pass
+    return current_app.config[config_key]
+
+
+def cmmc_usb_connection():
+    """Open a pymysql connection to the cmmc_usb DB."""
+    return pymysql.connect(
+        host=_setting_or_config('cmmc_usb_db_host', 'CMMC_USB_DB_HOST'),
+        user=_setting_or_config('cmmc_usb_db_user', 'CMMC_USB_DB_USER'),
+        password=current_app.config['CMMC_USB_DB_PASSWORD'],
+        database=_setting_or_config('cmmc_usb_db_name', 'CMMC_USB_DB_NAME'),
+        cursorclass=pymysql.cursors.DictCursor,
+    )