Adds await-then-play pattern: audio is pre-generated and cached before visuals appear, so log text + speech bubble + mouth animation + voice all fire in the same frame. Prefetches both answers during question playback for instant transitions. Adds hideSpeechBubble() to dismiss bubbles when voice ends instead of fixed 5s timer. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>