fix(locator): serialize mouse move/press/release CDP dispatch sequence (#2486)

[teddiesloco]

Summary

• Fixes v4: locator.click() returns without committing a selectable row #2486 by ensuring CDP mouse events (mouseMoved, mousePressed, mouseReleased) in Understudy.Locator.click are dispatched sequentially instead of being pipelined via Promise.all.
• Prevents race conditions where selectable component states (such as active hover/pointer states in React buttons/anchors) fail to commit before press/release.

Test Plan

• Verified sequential CDP input dispatch order.
• Verified cleanly formatted TS diff matching the repo's Understudy locator contract.

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Summary by cubic

Fixes #2486 by serializing the CDP mouse event dispatch sequence in Locator.click. Previously, mouseMoved, mousePressed, and mouseReleased were fired concurrently via Promise.all, which could let press/release execute before the browser committed hover or pointer states, causing missed clicks on React buttons and anchors. The events now run sequentially in order, with press/release repeated per click count as before.

^{Written for commit a5fcf49. Summary will update on new commits.}

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