GestureMenu horizontal swipe test flakes in Chromium #853

What is wrong

The Chromium browser test GestureMenu in chromium > a vertical drag scrolls the list and never swipes; a horizontal drag swipes without moving the layout failed once with TimeoutError: waitForFunction: Timeout 10000ms exceeded while waiting for row 8's --k2b-gesture-menu-offset to reach 79.5px. The same packages/ui code passed on the previous run of the same PR, and the failing branch changes only release files.

Seen in CI:

• https://github.com/k2b-dev/cloud/actions/runs/38044354688/job/114190940417 (release PR chore: release main #800, ui)

How to reproduce

# With a Playwright Chromium setup as in docs-site/docs/en/contributing/testing.md
bun run test --browser --filter gesture-menu

Intermittent. It failed once in the run above and in none of the last 25 failed CI runs.

Suspected cause

packages/ui/src/actions/gesture-menu.browser.test.ts:238-248: the horizontal drag starts right after still() from coordinates measured once, then waits for an exact offset on .k2b-gesture-menu index 8. The suspected cause is that the list or Chromium's gesture state from the first vertical drag has not settled yet. The touch then lands on a neighbouring row or Chromium cancels it as a scroll, so row 8 never reaches 79.5px. This is unverified.

Proposal

Let the test check which row received the press, and the pointercancel count, before it waits for the offset. Then wait for the touch to start on row 8, or re-measure from after the list has settled, so a failure names the real cause and does not time out.