* studio: set _stats_logger in kill-process test backend
#6377 added a self._stats_logger cleanup step to _kill_process's finally block.
test_kill_process_records_timestamp_on_actual_kill (added in #6400) builds the
backend via __new__, which bypasses __init__ where _stats_logger is set, so once
both landed on main the test raised AttributeError: 'LlamaCppBackend' object has
no attribute '_stats_logger'. Set _stats_logger on the hand-built backend,
mirroring __init__, so the kill path's finally has the attribute it expects.
* test: assert torchao override step on normal Linux, not overrides.txt
#6400 moved the torchao dependency override from a fixed pin in overrides.txt to
a torch-matched spec installed via --force-reinstall (_select_torchao_spec), and
turned overrides.txt into a comment-only pointer. It updated the Windows variant
(test_windows_only_includes_overrides) to check for --reinstall, but left
test_normal_linux_includes_overrides asserting overrides.txt is installed, which
no longer happens. Check for the override step (--reinstall) instead, matching
the Windows test.
* test(ui): tolerate ERR_ABORTED on /login re-login in shutdown step
The Shutdown step re-logs in after a CLI password rotation that revoked the prior
token. The SPA auth guard can client-side-redirect mid-navigation against the
stale token, aborting page.goto("/login") with net::ERR_ABORTED. It is a race
(passes on main most of the time). Resolve on domcontentloaded and tolerate the
abort, relying on the password-field wait that follows to confirm we reached
/login, matching the wait_until used by the other navigations in this file.