fix: Register reset_oauth_credentials route in admin_routes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: StuMason

src/polar_flow_server/admin/routes.py

@@ -1191,6 +1191,7 @@ async def export_cardio_load_csv(
     trigger_manual_sync,
     oauth_authorize,
     admin_settings,
+    reset_oauth_credentials,
     # Chart API endpoints
     chart_sleep_data,
     chart_activity_data,