The pre-push gate linted only the dirty tree, so the commits about to be pushed went
unchecked; and every failed overlay projection was sticky, which cost a finger result its
overlay over one bad frame while box results were retried nowhere. gate.ps1 now takes
-LintBase (default origin/main, exit 2 on an unknown ref), the projector declares whether
its own failures are permanent, and serve_stored_view decides before it sets the view.
Verified with gate.ps1 (PASS: 569 studio + 485 shared tests, 632 ui_check checks) and the
two round-2 red samples kept in scratch.
ykcheungab