feat: sync TTS voice with chat bubbles and battle log for zero-gap playback

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>

frontend/src/components/FightViewer.vue

@@ -10,6 +10,8 @@ import {
   setMasterMute, isMasterMuted, ensureAudioContext,
   speakQuestion, speakAnswer, speakNarration,
   prefetchQuestion, prefetchAnswer, prefetchNarration,
+  awaitQuestionReady, awaitAnswerReady,
+  playQuestionNow, playAnswerNow, playNarrationNow,
   sfxRandomComedy, sfxRandomFail, sfxVineBoom, sfxEmotionalDamage,
 } from '../game/audio'
 import { isKokoroLoading, getKokoroProgress } from '../game/tts'
@@ -400,60 +402,61 @@ async function _doReplay() {
       scene.startShowboating('b')
     }
 
-    // 1. Show question in log AND speak it (audio should be pre-generated by now)
+    // 1. Ensure question audio is ready BEFORE showing anything (zero-gap)
+    if (doTTS && questionText) {
+      // Kick off answer prefetches early so they generate in parallel
+      if (round.botAResponse) prefetchAnswer(props.fight.botA!.name, round.botAResponse)
+      if (round.botBResponse) prefetchAnswer(props.fight.botB!.name, round.botBResponse)
+      await awaitQuestionReady(questionText)
+    }
+    // Show question text + play voice at the exact same moment
     logItems.value.push(
       { type: 'header', round: round.roundNumber, text: `ROUND ${round.roundNumber}: ${challengeLabel(round.challengeType)}`, color: 'neon-purple' },
     )
-    scrollLog(); await sleep(insanityMode.value ? 30 : 100)
     logItems.value.push(
       { type: 'prompt', round: round.roundNumber, text: questionText, color: 'text-muted' },
     )
     scrollLog()
     if (doTTS && questionText) {
-      // Prefetch bot A answer while question plays
-      if (round.botAResponse) prefetchAnswer(props.fight.botA!.name, round.botAResponse)
-      await speakQuestion(questionText)
-      await sleep(150)
+      await playQuestionNow(questionText)
     } else {
-      await sleep(insanityMode.value ? 50 : 600)
+      await sleep(insanityMode.value ? 50 : 300)
     }
 
-    // 2. Bot A: log + bubble + mouth + TTS (all synced)
-    // Stop A's showboat when it's their turn to talk, B keeps showboating
+    // 2. Bot A: ensure audio ready, then show log + bubble + mouth + voice all at once
     if (round.botAResponse) {
+      if (doTTS) await awaitAnswerReady(props.fight.botA!.name, round.botAResponse)
       scene?.stopShowboating('a')
       logItems.value.push({ type: 'responseA', round: round.roundNumber, text: `${props.fight.botA?.name}: ${round.botAResponse.slice(0, 120) || '[NO RESPONSE]'}`, color: 'neon-cyan' })
       logItems.value.push({ type: 'time', round: round.roundNumber, text: `  ${round.botATimeMs}ms | Score: ${round.botAScore}`, color: 'text-muted' })
       scrollLog()
       if (scene && !insanityMode.value) {
-        scene.showSpeechBubble('a', round.botAResponse.slice(0, 60), 5)
+        scene.showSpeechBubble('a', round.botAResponse.slice(0, 60), 8)
         scene.startTalking('a')
       }
-      // Prefetch bot B answer while bot A talks
-      if (doTTS && round.botBResponse) prefetchAnswer(props.fight.botB!.name, round.botBResponse)
-      if (doTTS) await speakAnswer(props.fight.botA!.name, round.botAResponse)
-      else await sleep(insanityMode.value ? 30 : 800)
+      if (doTTS) await playAnswerNow(props.fight.botA!.name, round.botAResponse)
+      else await sleep(insanityMode.value ? 30 : 400)
       scene?.stopTalking('a')
-      if (!insanityMode.value) await sleep(150)
+      scene?.hideSpeechBubble('a')
     }
 
-    // 3. Bot B: log + bubble + mouth + TTS
-    // Stop B's showboat when it's their turn to talk
+    // 3. Bot B: ensure audio ready, then show log + bubble + mouth + voice all at once
     if (round.botBResponse) {
+      if (doTTS) await awaitAnswerReady(props.fight.botB!.name, round.botBResponse)
       scene?.stopShowboating('b')
       logItems.value.push({ type: 'responseB', round: round.roundNumber, text: `${props.fight.botB?.name}: ${round.botBResponse.slice(0, 120) || '[NO RESPONSE]'}`, color: 'neon-pink' })
       logItems.value.push({ type: 'time', round: round.roundNumber, text: `  ${round.botBTimeMs}ms | Score: ${round.botBScore}`, color: 'text-muted' })
       scrollLog()
-      if (scene && !insanityMode.value) {
-        scene.showSpeechBubble('b', round.botBResponse.slice(0, 60), 5)
-        scene.startTalking('b')
-      }
       // Prefetch narration while bot B talks
       if (doTTS && round.narration) prefetchNarration(round.narration)
-      if (doTTS) await speakAnswer(props.fight.botB!.name, round.botBResponse)
-      else await sleep(insanityMode.value ? 30 : 800)
+      if (scene && !insanityMode.value) {
+        scene.showSpeechBubble('b', round.botBResponse.slice(0, 60), 8)
+        scene.startTalking('b')
+      }
+      if (doTTS) await playAnswerNow(props.fight.botB!.name, round.botBResponse)
+      else await sleep(insanityMode.value ? 30 : 400)
       scene?.stopTalking('b')
-      if (!insanityMode.value) await sleep(150)
+      scene?.hideSpeechBubble('b')
     }
 
     // Stop all showboating before fight animation
@@ -815,14 +818,11 @@ async function _doReplay() {
           </svg>
         </button>
         <button
-          class="w-8 h-8 flex items-center justify-center border text-[9px] font-pixel tracking-wider transition-all"
-          :class="perfMode
-            ? 'border-neon-green/70 text-neon-green bg-neon-green/10'
-            : 'border-border/50 text-text-muted hover:text-neon-green hover:border-neon-green/50'"
-          :title="perfMode ? 'Performance mode ON (fewer particles)' : 'Performance mode OFF'"
+          class="h-8 px-2 flex items-center justify-center border text-[9px] font-pixel tracking-wider transition-all border-neon-green/70 text-neon-green bg-neon-green/10"
+          :title="perfMode ? 'Performance mode ON (fewer particles)' : 'Performance mode OFF (full effects)'"
           @click="togglePerfMode"
         >
-          {{ perfMode ? 'LO' : 'HI' }}
+          {{ perfMode ? 'Lo GFX' : 'Hi GFX' }}
         </button>
         <button
           v-if="isReplaying"
@@ -833,7 +833,7 @@ async function _doReplay() {
           title="INSANITY MODE: Skip TTS, max speed"
           @click="toggleInsanity"
         >
-          {{ insanityMode ? 'INSANITY' : 'SKIP' }}
+          {{ insanityMode ? 'INSANITY' : 'REGULAR' }}
         </button>
         <!-- Zap winner button -->
         <button

frontend/src/game/FightScene.ts

@@ -734,6 +734,19 @@ export async function createFightScene(config: FightSceneConfig) {
     }, duration * 1000)
   }
 
+  function hideSpeechBubble(side: 'a' | 'b') {
+    const els = side === 'a' ? activeBubbleA : activeBubbleB
+    if (!els.length) return
+    els.forEach(el => {
+      if (!el.exists()) return
+      k.tween(el.opacity, 0, 0.25, (v) => { el.opacity = v }).then(() => {
+        if (el.exists()) el.destroy()
+      })
+    })
+    if (side === 'a') activeBubbleA = []
+    else activeBubbleB = []
+  }
+
   function wrapBubbleText(text: string, maxChars: number): string[] {
     const words = text.split(' ')
     const lines: string[] = []
@@ -1195,6 +1208,7 @@ export async function createFightScene(config: FightSceneConfig) {
     showSpeechBubble(side: 'a' | 'b', text: string, duration?: number) {
       showSpeechBubble(side, text, duration)
     },
+    hideSpeechBubble(side: 'a' | 'b') { hideSpeechBubble(side) },
 
     startTalking(side: 'a' | 'b') { startTalking(side) },
     stopTalking(side: 'a' | 'b') { stopTalking(side) },

frontend/src/game/audio/index.ts

@@ -205,6 +205,11 @@ export {
   prefetchQuestion,
   prefetchAnswer,
   prefetchNarration,
+  awaitQuestionReady,
+  awaitAnswerReady,
+  playQuestionNow,
+  playAnswerNow,
+  playNarrationNow,
 } from './voice'
 
 // music

frontend/src/game/audio/voice.ts

@@ -2,7 +2,7 @@
 
 import { getCtx, getSfxDest, getMasterMuted, getSfxGain } from './context'
 import { tone, noise } from './primitives'
-import { initKokoro, isKokoroReady, kokoroSpeak, kokoroSpeakAsync, kokoroStop, kokoroPrefetch, setAudioContext } from '../tts'
+import { initKokoro, isKokoroReady, kokoroSpeak, kokoroSpeakAsync, kokoroStop, kokoroPrefetch, kokoroAwaitReady, kokoroPlayCached, setAudioContext } from '../tts'
 
 // === VOICE PROFILES ===
 
@@ -756,6 +756,48 @@ export function prefetchNarration(text: string) {
   kokoroPrefetch(smartTruncate(text, 200), 'sportscaster')
 }
 
+// === AWAIT + PLAY-NOW pattern for tight sync ===
+// Call awaitReady to block until audio is generated, then playNow fires instantly
+
+export async function awaitQuestionReady(text: string): Promise<void> {
+  if (getMasterMuted()) return
+  const trimmed = smartTruncate(text, 200)
+  if (isKokoroReady()) await kokoroAwaitReady(trimmed, 'question_reader')
+}
+
+export async function awaitAnswerReady(botName: string, answer: string): Promise<void> {
+  if (getMasterMuted()) return
+  const trimmed = smartTruncate(answer, 200)
+  if (isKokoroReady()) await kokoroAwaitReady(trimmed, botVoiceKey(botName))
+}
+
+export function playQuestionNow(text: string): Promise<void> {
+  const trimmed = smartTruncate(text, 200)
+  return _playNowCore(trimmed, 'question_reader')
+}
+
+export function playAnswerNow(botName: string, answer: string): Promise<void> {
+  const trimmed = smartTruncate(answer, 200)
+  return _playNowCore(trimmed, botVoiceKey(botName), 1.15)
+}
+
+export function playNarrationNow(text: string): Promise<void> {
+  const trimmed = smartTruncate(text, 200)
+  return _playNowCore(trimmed, 'sportscaster', 1.2)
+}
+
+async function _playNowCore(text: string, profileName: string, rateOverride?: number): Promise<void> {
+  if (getMasterMuted()) return
+  const sfxGain = getSfxGain()
+  if (isKokoroReady() && sfxGain) {
+    const profile = voiceProfiles[profileName] || voiceProfiles.announcer
+    await kokoroPlayCached(text, profileName, sfxGain, profile.volume * VOICE_VOLUME_SCALE)
+    return
+  }
+  // Fallback to Web Speech
+  return _speakAsyncCore(text, profileName, rateOverride)
+}
+
 // Re-export TTS utilities needed by ensureAudioContext (in index.ts)
 export { initKokoro, setAudioContext, loadVoices as _loadVoices }
 

frontend/src/game/tts.ts

@@ -376,6 +376,33 @@ export function kokoroPrefetch(text: string, profileName: string): void {
   _generateAndCache(text, profileName).catch(() => {})
 }
 
+/** Await until prefetched audio is cached and ready. Returns true if cached, false on failure. */
+export async function kokoroAwaitReady(text: string, profileName: string): Promise<boolean> {
+  if (!_workerReady) return false
+  try {
+    const buf = await _generateAndCache(text, profileName)
+    return !!buf
+  } catch { return false }
+}
+
+/** Play already-cached audio immediately. Returns playback promise. If not cached, returns resolved. */
+export function kokoroPlayCached(
+  text: string,
+  profileName: string,
+  dest: AudioNode,
+  volume: number = 0.7,
+): Promise<void> {
+  if (!_workerReady) return Promise.resolve()
+  const key = _cacheKey(text, profileName)
+  const cached = audioCache.get(key)
+  if (cached) {
+    cached.lastAccess = Date.now()
+    return _playBuffer(cached.buf, dest, volume)
+  }
+  // Not cached — fall through to generate+play
+  return kokoroSpeakAsync(text, profileName, dest, volume).then(() => {})
+}
+
 /** Stop all currently playing kokoro audio */
 export function kokoroStop() {
   for (const src of activeSources) {