Device logs showed Android's interactive-widget=resizes-content already shrinks
the layout viewport to above the keyboard (innerHeight 800->472 for a 328px
keyboard), yet the app also lifted the composer by --kb=328 → a keyboard-height
white gap. Now gate the manual --kb lift to iOS only (WKWebView doesn't resize);
on Android keep --kb=0 and just toggle kb-open so --sab collapses and the composer
sits flush to the keyboard. Also removes the temporary kbdiag logging.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>