Using last iteration's recipe (first title, one (A)) four more times, it failed
every time. The nine-run table splits perfectly on --log_ui_draws: 3 of 3
successes without it, 0 of 5 with it. That would indict my own instrumentation
cvar, which is the one that captures paint order.
It is also perfectly confounded and the entry says so rather than picking the
exciting reading: every success had its title inside 147 s, every failure at
177 s or later. Flag and boot-time move together across all nine runs. A
mechanism is hard to see for the flag (it is read only when F10 arms a capture;
the per-draw hook is one relaxed atomic load), which argues for the boot-time
story — but "I cannot see how" is not evidence.
The separating experiment is named: ON runs with a fast boot. One that accepts
(A) exonerates the flag.
Also recorded: widening the menu signature last commit made screen_id classify
some boot frames as "menu", twice in one run before any menu existed. A dark-blue
movie frame and this menu are not separable from a single grab — navigation
scripts need the classification to hold across two grabs, which is a caller-side
fix, not a classifier one.
8dbfeb97df