test: terminal-arrows-clicks-regression.ts:194 latency bound flakes in CI #668

The 150 ms bound at scripts/terminal-arrows-clicks-regression.ts:194 (added by #634) fails intermittently on GitHub-hosted runners: 198.9 ms on the v0.4.3 release PR #664 (first Integration attempt; the rerun passed) and the same failure on main at 2d80d3b (run 37897884642). It is a required check, so a flake blocks merges.

The assertion measures wall-clock latency on a shared runner. Options: assert ordering and delivery only and record the latency as a timing line (the browser lane already prints per-script timings since #627), or measure against a baseline taken in the same run instead of a fixed 150 ms.