The current page id was only injected as text in the system prompt, which a
proxy (CLIProxyAPI) can rewrite/truncate, so the agent could lose track of 'this
page'. Add a getCurrentPage tool the model can call to read the open page (id +
title) from the server-side request context (forUser now takes openedPage,
threaded from body.openPage — the same value used for the system prompt). The
inline system-prompt line is kept as belt-and-suspenders. Reads/writes still go
through the CASL-enforced page tools by id, so this is strictly not worse than
the existing prompt hint — just delivered over a channel the proxy can't mangle.
User-approved on the issue. Completes #43 together with the hardness-1 fix.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>