The session's active tab was a bare index into `pages`, which drifts when a
foreign/user/other-session tab is passively discovered, a tab closes, or the list
reorders — so `eval`/`screenshot`/`snapshot`/`click` could land on the wrong page.
With login state that's a safety bug (a fetch firing on the wrong origin), and it
made screenshot disagree with snapshot/eval.
Pin the intended tab by stable target_id (`active_target_id`), set on every
explicit open / tab new / tab switch / connect. `active_session_id` and
`active_target_id` resolve through it (falling back to the index only if the
pinned tab is gone), so all commands stick to the agent's tab regardless of
passive churn — and they all agree.
Verified (--cdp, multi-tab): a window.open foreign tab no longer drifts eval;
tab new / switch re-pin correctly.
leeguooooo
d7a0ed85f9