fix: human fight timing, creative timer, TTS reliability, add sweary/vibe narrations

- Fix invisible characters in human mode: init live scene BEFORE starting
  challenge polling so entrance plays before first question appears
- Cap creative writing timer to 10s for multiple choice (just tapping buttons)
- Fix TTS reliability: precache priority phrases (Round 1-7, Fight!, K.O.)
  all at once instead of in slow batches; prevent duplicate precache runs
- Add 10 vibe-coded narrations (~20% chance): "I was vibe coded into existence"
- Add 15 sweary narrations (~30% chance): raw unhinged fight commentary
- Add sweary draw and retro narrations

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

frontend/src/pages/HumanFightPage.vue

@@ -188,7 +188,9 @@ async function pollForChallenge() {
         showTrashTalk.value = false
         feedback.value = null
         phase.value = 'challenge'
-        startTimer(data.remainingMs)
+        // Cap timer for multiple choice — just tapping a button, not typing
+        const timerMs = (data.choices?.length > 0) ? Math.min(data.remainingMs, 10000) : data.remainingMs
+        startTimer(timerMs)
         await nextTick()
         if (!hasChoices.value) answerInput.value?.focus()
       }