Dismiss caret on Android when the virtual keyboard is closed without blur

[Copilot]

On Android, dismissing the virtual keyboard with the Down Arrow button hides the keyboard without blurring the editable, so no blur event fires and the caret keeps blinking on the thought.

Root cause

src/util/handleKeyboardVisibility.ts already detects the keyboard closing from a visualViewport resize and exits edit mode (clears the selection, sets isKeyboardOpen: false), but it was never attached to any listener — effectively dead code. The only resize listener wired (updateSize) does not touch the caret, and Android has no active virtual-keyboard handler (iOSSafariHandler early-returns when not Safari).

Changes

• src/util/initEvents.ts — wire handleKeyboardVisibility to the resize event alongside the existing updateSize listener, with matching teardown in cleanup.

  const resizeHost = window.visualViewport || window
  resizeHost.addEventListener('resize', updateSize)
  // On Android, dismissing the virtual keyboard (e.g. via the Down Arrow button) hides the keyboard
  // without blurring the editable, so no blur event fires to dismiss the caret. Detect the keyboard
  // closing from the viewport resize and exit edit mode.
  resizeHost.addEventListener('resize', handleKeyboardVisibility)

• src/e2e/puppeteer/__tests__/caret.ts — regression test in the mobile only block simulating a keyboard-open then Down-Arrow dismiss (viewport resize without blur), asserting the selection is cleared.

Cross-platform safety

The handler is touch-gated (no-op on desktop), throttled, only acts when isKeyboardOpen && cursor, and ignores rotation (currentWidth === lastViewportWidth). On iOS the keyboard close fires blur first (Editable.tsx dispatches keyboardOpen({ value: false })), so the resize handler runs as a no-op there.

[BayuAri]

Confirm fixed.
Caret is auto dismissed along with keyboard when closed from down arrow on the nav bar.