fix(preview): agent browser tabs show one page and work while hidden#22877

test(web): drop the issue 16901 manual reproduction fixture

Merge main into t3/agent-browser-one-page

test(web): issue 16901 fixture native-hidden steps use the configured port

test: move preview evidence fixture under web test fixtures

test: follow node import convention in evidence fixture

test: correct preview evidence reproduction commands

test: add reproducible preview evidence fixture

merge: update browser fix with main

merge: reuse existing fix for issue 16901

fix(web): a tab that turned headless ignores its old desktop page state

fix(preview): agent browser tabs show one page and work while hidden