Debug confirmed resize:native shrinks the WebView by the keyboard height, so the composer only needs the
residual lift = clientHeight - visualViewport.height (46px on the test device — the prediction-bar sliver).
Tracked live via VisualViewport so it follows the keyboard. Zero per-device constants. Removed debug bar;
reverted Keyboard config to resize:native (which the logic relies on).
Build marker -> 2026-07-18-batch105.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>