GenClass: see the race, replay it, prove the fix

GenClass records what happens inside the app's pages on this machine (each click, request, the order responses were delivered, what each response wrote into the state, uncaught errors with the click and request behind them), can run the page again with responses delivered in different orders, and can replay one exact order. It needs Claude Code (or another MCP client) on the developer's machine, next to the app's dev server; the chat app cannot run it. The server's instructions say when to reach for it; this file is the procedure.

0. Check the connection

Call genclass_status. If no page is listed, call genclass_setup and add the two lines it shows to the app's browser entry (development builds only), then load a page of the dev server.

1. From a finding to a proven fix