cmux-next: close batch B1 test windows
Closed
TE
7d ago+587+587+012345678901234567890123456789-143-143-012345678901234567890123456789
Batch B1 closes the remaining Swift test windows and panels that were still kept alive after each test. This follows Leo's instruction: "But why do you guys not just clean up after yourselves, or at least do your best to?"
The suites close their own windows and popup panels in teardown, while the product-side cleanup keeps Page Info, Extensions Menu, Host Pressure, Native Popup, and browser retirement panels from surviving a window close. This branch is stacked after the merged overlay-host fix.
No capture: no visible change; these changes only close hidden panels and test windows after their owner closes.
| metric | before | after | delta | harness or run link |
|---|---|---|---|---|
| Windows open at process exit | 251 | pending | pending | five-step fleet census harness |
Agent session: agent session