Two _CountingNatureOverlay draw-spy tests (the PR #196 pattern):
window arrival and rung-swap arrival both advance the nature
overlay's draw count past baseline. Two isolation bugs caught before
reporting: (1) _on_window_ready has a second pre-existing redraw path
via _fit_and_center -> _apply_transform that fires on first arrivals
and masks a sabotaged line 507 — isolated by setting _user_adjusted
(the real pan/zoom guard, a reachable state); (2) simulating the swap
via _enter_at_rung resets _awaiting_first_window and takes the same
masked branch — the real production trigger is _maybe_reselect_rung's
request path, so the test drives request_now directly. Revert-
verified: dropping the queue_redraw line fails exactly both tests by
name; 82/82 restored. Viewer file itself zero net diff.
Tickets: T-1170
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
jpmschweitzerandClaude Fable 5
581be31549
