Written up from the debugging sessions that fixed the IME commit
corruption, the scroll slowdown, the mid-word caps, and the
distant-commit clobbering: the three-model mental model, the
invariants, the stock-gioui structural behaviors the design works
around (post-commit selection dedup, restartInput shadowing,
focus-gated selection commands, no acks), the log signatures, the
test-layer coverage table, and the operational pitfalls hit along
the way.
