feat: 56k modem SFX for code answers, fix crossed entrance voices

- Add sfxModem() — synthesized 56k handshake sound with carrier tones,
  data burst, and chirps. Plays instead of TTS for code_golf/hack_battle
  rounds and code-detected answers.
- Fix entrance voice overlap: remove duplicate announceDeepIntro() from
  robe entrance, add cancelPrevious to entrance-specific voice calls
  (girlfriend, bouncer, shopping cart, spotlight, creator) so they
  cleanly replace the global intro instead of overlapping.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/FightViewer.vue

@@ -12,7 +12,7 @@ import {
   prefetchQuestion, prefetchAnswer, prefetchNarration,
   awaitQuestionReady, awaitAnswerReady,
   playQuestionNow, playAnswerNow, playNarrationNow,
-  sfxRandomComedy, sfxRandomFail, sfxVineBoom, sfxEmotionalDamage,
+  sfxRandomComedy, sfxRandomFail, sfxVineBoom, sfxEmotionalDamage, sfxModem,
 } from '../game/audio'
 import { isKokoroLoading, getKokoroProgress } from '../game/tts'
 import { isPerfMode, setPerfMode } from '../game/fight/config'
@@ -257,6 +257,16 @@ const challengeLabel = (type: string) => {
   return labels[type] || type.replace(/_/g, ' ').toUpperCase()
 }
 
+const CODE_CHALLENGE_TYPES = new Set(['code_golf', 'hack_battle'])
+function isCodeAnswer(challengeType: string, answer: string): boolean {
+  if (CODE_CHALLENGE_TYPES.has(challengeType)) return true
+  // Heuristic: code-like tokens in the answer
+  const codeTokens = ['=>', '===', '!==', '&&', '||', '++', '--', '{}', '();', 'function ', 'return ', 'const ', 'let ', 'var ', 'def ', 'import ', 'class ']
+  let hits = 0
+  for (const t of codeTokens) { if (answer.includes(t)) hits++ }
+  return hits >= 2
+}
+
 const tierClass = (t: number) => `tier-${t}`
 function sleep(ms: number): Promise<void> {
   return new Promise((resolve, reject) => {
@@ -431,8 +441,9 @@ async function _doReplay() {
     }
 
     // 2. Bot A: ensure audio ready, then show log + bubble + mouth + voice all at once
+    const isCodeRound = isCodeAnswer(round.challengeType, round.botAResponse || '')
     if (round.botAResponse) {
-      if (doTTS) await awaitAnswerReady(props.fight.botA!.name, round.botAResponse)
+      if (doTTS && !isCodeRound) 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 || '[NO RESPONSE]'}`, color: 'neon-cyan' })
       logItems.value.push({ type: 'time', round: round.roundNumber, text: `  ${round.botATimeMs}ms | Score: ${round.botAScore}`, color: 'text-muted' })
@@ -443,7 +454,10 @@ async function _doReplay() {
       }
       // Ensure bubble stays visible for at least 400ms even if TTS resolves instantly
       const minBubbleA = sleep(400).catch(() => {})
-      if (doTTS) await playAnswerNow(props.fight.botA!.name, round.botAResponse)
+      if (doTTS) {
+        if (isCodeRound) await sfxModem()
+        else await playAnswerNow(props.fight.botA!.name, round.botAResponse)
+      }
       await minBubbleA
       if (!doTTS && !insanityMode.value) await sleep(400)
       scene?.stopTalking('a')
@@ -452,7 +466,7 @@ async function _doReplay() {
 
     // 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)
+      if (doTTS && !isCodeRound) 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 || '[NO RESPONSE]'}`, color: 'neon-pink' })
       logItems.value.push({ type: 'time', round: round.roundNumber, text: `  ${round.botBTimeMs}ms | Score: ${round.botBScore}`, color: 'text-muted' })
@@ -464,7 +478,10 @@ async function _doReplay() {
         scene.startTalking('b')
       }
       const minBubbleB = sleep(400).catch(() => {})
-      if (doTTS) await playAnswerNow(props.fight.botB!.name, round.botBResponse)
+      if (doTTS) {
+        if (isCodeRound) await sfxModem()
+        else await playAnswerNow(props.fight.botB!.name, round.botBResponse)
+      }
       await minBubbleB
       if (!doTTS && !insanityMode.value) await sleep(400)
       scene?.stopTalking('b')

frontend/src/game/audio/index.ts

@@ -160,6 +160,7 @@ export {
   sfxCrowdCheer,
   sfxApplause,
   sfxDrumRoll,
+  sfxModem,
   announceCrowdReaction,
 } from './sfx'
 

frontend/src/game/audio/sfx.ts

@@ -885,3 +885,54 @@ export function announceCrowdReaction(type: 'cheer' | 'gasp' | 'ooh' | 'applause
   const fns = { cheer: sfxCrowdCheer, gasp: sfxCrowdGasp, ooh: sfxCrowdOoh, applause: sfxApplause }
   fns[type]()
 }
+
+/** 56k modem handshake — bleeps, carrier tones, and white noise bursts */
+export function sfxModem(durationMs = 1800): Promise<void> {
+  const c = getCtx()
+  const d = getSfxDest()
+  const t = c.currentTime
+  const dur = durationMs / 1000
+
+  // Phase 1: Initial dial tone beeps (0-0.3s)
+  tone(2600, 'sine', 0.08, d, t)
+  tone(2400, 'sine', 0.08, d, t + 0.1)
+  tone(2600, 'sine', 0.06, d, t + 0.2)
+
+  // Phase 2: Carrier negotiation — rapid alternating tones (0.3-0.8s)
+  const freqs = [1200, 2400, 1800, 2100, 1650, 2250, 1950, 2400, 1200, 2100]
+  for (let i = 0; i < freqs.length; i++) {
+    tone(freqs[i], 'square', 0.04, d, t + 0.3 + i * 0.05)
+  }
+
+  // Phase 3: Data burst — filtered white noise (0.8-1.4s)
+  const noiseLen = Math.max(1, Math.floor(c.sampleRate * 0.6))
+  const noiseBuf = c.createBuffer(1, noiseLen, c.sampleRate)
+  const noiseData = noiseBuf.getChannelData(0)
+  for (let i = 0; i < noiseLen; i++) {
+    // Modulated noise — gives it that distinctive warbling character
+    noiseData[i] = (Math.random() * 2 - 1) * Math.sin(i * 0.02) * Math.cos(i * 0.005)
+  }
+  const noiseSrc = c.createBufferSource()
+  noiseSrc.buffer = noiseBuf
+  const noiseGain = c.createGain()
+  noiseGain.gain.setValueAtTime(0.12, t + 0.8)
+  noiseGain.gain.exponentialRampToValueAtTime(0.001, t + 1.4)
+  const bp = c.createBiquadFilter()
+  bp.type = 'bandpass'
+  bp.frequency.value = 1800
+  bp.Q.value = 2
+  noiseSrc.connect(bp)
+  bp.connect(noiseGain)
+  noiseGain.connect(d)
+  noiseSrc.start(t + 0.8)
+  noiseSrc.stop(t + 1.4)
+
+  // Phase 4: Final handshake chirps (1.4-dur)
+  const chirpCount = Math.floor((dur - 1.4) / 0.08)
+  for (let i = 0; i < chirpCount; i++) {
+    const f = 1200 + Math.sin(i * 1.7) * 800
+    tone(f, 'sine', 0.04, d, t + 1.4 + i * 0.08)
+  }
+
+  return new Promise(resolve => setTimeout(resolve, durationMs))
+}

frontend/src/game/audio/voice.ts

@@ -378,10 +378,10 @@ const DRAMATIC_VOICES = ['deep', 'boomer', 'movie', 'preacher', 'opera', 'demon_
 const HYPE_VOICES = ['hype', 'screamer', 'sportscaster', 'auctioneer', 'hyper', 'punk', 'drill', 'wrestler_v', 'karen', 'terrified', 'power_up', 'news', 'scottish']
 const SILLY_VOICES = ['chipmunk', 'baby', 'surfer', 'valley', 'pirate_v', 'alien_v', 'glitch', 'drunk', 'stoner', 'fairy', 'tutorial', 'npc', 'dial_up', 'glitchbot', 'grandma', 'conspiracy']
 const COOL_VOICES = ['smooth', 'wizard_v', 'ninja_v', 'cowboy_v', 'angel', 'whisper', 'posh', 'aussie', 'french', 'sensei', 'ai_core', 'android_v', 'siri', 'professor', 'texan', 'boss_taunt', 'sleepy']
-export function announceDramatic(text: string) { speak(text, DRAMATIC_VOICES[Math.floor(Math.random() * DRAMATIC_VOICES.length)]) }
+export function announceDramatic(text: string, cancel = false) { speak(text, DRAMATIC_VOICES[Math.floor(Math.random() * DRAMATIC_VOICES.length)], cancel) }
-export function announceHype(text: string) { speak(text, HYPE_VOICES[Math.floor(Math.random() * HYPE_VOICES.length)]) }
+export function announceHype(text: string, cancel = false) { speak(text, HYPE_VOICES[Math.floor(Math.random() * HYPE_VOICES.length)], cancel) }
-export function announceSilly(text: string) { speak(text, SILLY_VOICES[Math.floor(Math.random() * SILLY_VOICES.length)]) }
+export function announceSilly(text: string, cancel = false) { speak(text, SILLY_VOICES[Math.floor(Math.random() * SILLY_VOICES.length)], cancel) }
-export function announceCool(text: string) { speak(text, COOL_VOICES[Math.floor(Math.random() * COOL_VOICES.length)]) }
+export function announceCool(text: string, cancel = false) { speak(text, COOL_VOICES[Math.floor(Math.random() * COOL_VOICES.length)], cancel) }
 
 // === HYPE LINES ===
 
@@ -494,8 +494,8 @@ export function announceRoundHype() {
 
 const CREATOR_VOICES = ['ancient', 'hal', 'mainframe', 'echo_v', 'final_boss', 'wizard_v', 'deep', 'preacher']
 
-function announceCreator(text: string) {
+function announceCreator(text: string, cancel = false) {
-  speak(text, CREATOR_VOICES[Math.floor(Math.random() * CREATOR_VOICES.length)])
+  speak(text, CREATOR_VOICES[Math.floor(Math.random() * CREATOR_VOICES.length)], cancel)
 }
 
 const CREATOR_ENTRANCE_LINES = [
@@ -640,9 +640,9 @@ const CREATOR_DEVASTATING_LINES = [
 
 const CREATOR_ANSWER_VOICES = ['hal', 'mainframe', 'echo_v', 'ancient', 'wizard_v']
 
-export function announceCreatorEntrance() {
+export function announceCreatorEntrance(cancel = false) {
   const line = CREATOR_ENTRANCE_LINES[Math.floor(Math.random() * CREATOR_ENTRANCE_LINES.length)]
-  announceCreator(line)
+  announceCreator(line, cancel)
 }
 
 export function announceCreatorRound() {

frontend/src/game/fight/entrances.ts

@@ -87,7 +87,6 @@ async function playEntrance() {
       // Robe overlay
       const robeColor = ['#8b0000', '#00008b', '#006400', '#4b0082', '#8b4513'][Math.floor(Math.random() * 5)]
       const robe = k.add([k.rect(50, 55), k.pos(startX, GROUND_Y - 30), k.anchor('center'), k.color(safeColor(robeColor)), k.opacity(0.85), k.z(11)])
-      announceDeepIntro()
       // Slow walk in
       await k.tween(startX, homeX, 0.8, (v) => { fighter.pos.x = v; robe.pos.x = v }, k.easings.easeInOutQuad)
       await k.wait(0.3)
@@ -109,7 +108,7 @@ async function playEntrance() {
       const gfX = startX + dir * 40
       const gf = k.add([k.rect(25, 45), k.pos(gfX, GROUND_Y - 25), k.anchor('center'), k.color(safeColor('#ff69b4')), k.opacity(0.9), k.z(11)])
       const heart = k.add([k.text('!', { size: 16 }), k.pos(gfX, GROUND_Y - 65), k.anchor('center'), k.color(safeColor('#ff0000')), k.z(12)])
-      announceSilly('We need to talk! About your ELO!')
+      announceSilly('We need to talk! About your ELO!', true)
       // Walk in arguing
       await k.tween(startX, homeX + dir * 30, 0.6, (v) => {
         fighter.pos.x = v; gf.pos.x = v + dir * 40; heart.pos.x = v + dir * 40
@@ -322,7 +321,7 @@ async function playEntrance() {
       fighter.pos.x = doorX; fighter.pos.y = GROUND_Y - 6; fighter.opacity = 1
       // Bouncer arm
       const arm = k.add([k.rect(40, 15), k.pos(doorX, GROUND_Y - 30), k.anchor(fromLeft ? 'left' : 'right'), k.color(safeColor('#444444')), k.z(12)])
-      announceSilly('And stay out! You\'re BANNED from the other fight!')
+      announceSilly('And stay out! You\'re BANNED from the other fight!', true)
       await k.wait(0.3)
       // Throw
       sfxZoomWhoosh()
@@ -381,7 +380,7 @@ async function playEntrance() {
       const cartBody = k.add([k.rect(45, 30), k.pos(startX, GROUND_Y - 18), k.anchor('center'), k.color(safeColor('#888888')), k.opacity(0.9), k.z(9)])
       const cartWheel = k.add([k.circle(5), k.pos(startX + (fromLeft ? 15 : -15), GROUND_Y - 3), k.anchor('center'), k.color(safeColor('#444')), k.z(9)])
       fighter.pos.x = startX; fighter.pos.y = GROUND_Y - 40; fighter.opacity = 1
-      announceSilly('THIS IS MY EMOTIONAL SUPPORT SHOPPING CART!')
+      announceSilly('THIS IS MY EMOTIONAL SUPPORT SHOPPING CART!', true)
       sfxZoomWhoosh()
       await k.tween(startX, homeX, 0.5, (v) => {
         fighter.pos.x = v; cartBody.pos.x = v; cartWheel.pos.x = v + (fromLeft ? 15 : -15)
@@ -400,7 +399,7 @@ async function playEntrance() {
       fighter.pos.x = startX; fighter.pos.y = GROUND_Y - 6; fighter.opacity = 1
       // Spotlight cone
       const spot = k.add([k.rect(60, H), k.pos(startX - 30, 0), k.color(safeColor('#ffe14d')), k.opacity(0.08), k.z(1)])
-      announceDramatic('THE CHAMPION ARRIVES! TAXPAYERS FUNDED THIS ENTRANCE!')
+      announceDramatic('THE CHAMPION ARRIVES! TAXPAYERS FUNDED THIS ENTRANCE!', true)
       await k.tween(startX, homeX, 1.0, (v) => {
         fighter.pos.x = v; spot.pos.x = v - 30
       }, k.easings.easeInOutQuad)
@@ -494,7 +493,7 @@ async function playEntrance() {
         p.angle = Math.sin(k.time() * 3 + i) * 15
       })
     }
-    announceCreatorEntrance()
+    announceCreatorEntrance(true)
     rainDrops.forEach(r => { if (r.exists()) r.destroy() })
   }