# Third attempt at the three submenus' focus persistence. ❔ STILL UNMEASURED.
# 2026-08-31. VOID, and this time the cause was ME, not the instrument.
#
# The tool was reworked to fix both earlier failures -- decision on the region
# that CHANGED when the cursor moved (no per-screen geometry), and a NARROW
# back-on-the-menu test by ring row (the thing that kept reading correctly under
# a crash dialog). The rework was controlled on the EXTRAS frames whose answer is
# known, and passed.
#
# 🔴 WHAT WENT WRONG. While the run was in flight I edited the sweep script, and
# deliberately broke its decision rule with `sed` to test whether the new
# self-test could fail. The sweep reads the script when IT starts -- after the
# reach probe finishes -- and it started during that window. It read the broken
# rule.
#
# ✅ THE SELF-TEST CAUGHT IT AND REFUSED TO RUN:
#     ✅ known RESETS (real EXTRAS triple)    -> RESETS    (want RESETS)
#     🔴 constructed PERSISTS                 -> RESETS    (want PERSISTS)
#     ✅ constructed RESETS                   -> RESETS    (want RESETS)
#     🔴 SELF-TEST FAILED — the rule cannot produce both verdicts.
#
# That is the self-test's first save, on the day it was written, against a fault
# I introduced. Without it the sweep would have reported "RESETS" for all three
# screens -- a confident, uniform, entirely fabricated answer.
#
# ⚠️ THREE FURTHER SELF-INFLICTED FAULTS, recorded because they are process, not
# analysis, and process is what failed here:
#
#   1. I ran a competing test that opened x11grab captures on the same display
#      DURING a measurement run -- the exact concurrency confound sylpheed-port
#      had warned cost them a 7-percentage-point swing. Even had the sweep
#      completed, its timings would carry that.
#   2. I then cleared the strays with `pkill -f x11grab`, which can kill the
#      running sweep's own capture. METHOD.md already records `pkill -f` matching
#      the caller's shell; this is the same pattern biting a different way.
#   3. My restore of the broken file sat as the LAST line of a command that timed
#      out, so it never ran, and the broken rule stayed on disk. Recovering with
#      `git checkout` then discarded the whole uncommitted rework.
#
# 📌 THE PROCESS FIX, applied: the tool is COMMITTED BEFORE IT IS RUN. An
# uncommitted tool is one timed-out command away from being unrecoverable, and a
# tool edited during its own run is not the tool that ran.
#
# ❔ The reach probe also timed out ("TIMEOUT in phase remenu"), so the menu was
# never reached in this boot either. Whether that is ordinary boot variance or my
# added load, I cannot separate -- which is itself the cost of point 1.