The new topbar badge on the Chat tab (chatThreadCount > 0) broke the
old /^\\s*Chat\\s*$/ regex. Switched to a Playwright filter chain:
.tab filtered by hasText 'Chat' AND hasNotText 'Assistant' (which also
contains 'Chat' substring elsewhere in DOM). All 4 QA suites green:
- 36/36 dogfood (chat_sidebar threads=8 previews=8 times=8)
- 12/12 buyer-script (Approvals action disabled? true)
- 8/8 idle-poll (0 reqs at 30s on every scene)
- 14/14 mobile (390px clean)
