WJ import loader: mark setup_complete (a full import is the setup)

A freshly-imported DB left setup_complete unset, so the admin was bounced into
the first-run wizard even though the instance is fully populated. The harness now
sets setup_complete=true (it already mints the admin), so an imported instance
goes straight to the app.

scripts/site_imports/wjf/harness.py

@@ -118,6 +118,10 @@ class Harness:
                 plugin.on_install(self.app)
             except Exception:
                 pass
+        # A full import IS the setup, so mark it complete - otherwise the admin
+        # is bounced to the first-run wizard on every fresh import DB.
+        from shopdb.core.models import Setting
+        Setting.set('setup_complete', 'true', valuetype='boolean', category='site')
         db.session.commit()
 
     def _mint_admin_pat(self):