feat: v5 — boxing poster fight cards, 12-char names, diverse mock bots

- Fight Card page: dramatic poster background with cross-hatch, spotlights,
  vignettes, corner brackets, scan lines; 3D VS orb with punch animation;
  selectable undercard with main event always pinned at top
- PosterSprite: high-quality 480px poster frame with 6-pass renderer
  (aura, glow, bevel, specular, particles); PixelGlove component
- 12-char bot name limit across all forms and server validation
- Mock bots: all 100 now have diverse archetypes (25 types), 25% human
  fighters; seedMockBots updates existing bots on restart
- Leaderboard: inline SpritePreview next to each bot name
- Nostr auth: persistent login, nsec copy button
- Wallet: NWC + Lightning Address, ranked fight flow
- Server: payments, ranked queue, customization endpoint

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

frontend/src/pages/FightPage.vue

@@ -153,7 +153,15 @@ const myBotId = computed(() => {
 
 const showOverlay = computed(() => replayDone.value && !isRequeueing.value && !autoBattle.value)
 
-function sleep(ms: number) { return new Promise(resolve => setTimeout(resolve, ms)) }
+let _pageDestroyed = false
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve, reject) => {
+    setTimeout(() => {
+      if (_pageDestroyed) reject(new Error('unmounted'))
+      else resolve()
+    }, ms)
+  })
+}
 function scrollLiveLog() { nextTick(() => { liveLogEl.value?.scrollTo({ top: liveLogEl.value.scrollHeight, behavior: 'smooth' }) }) }
 
 const challengeLabel = (type: string) => {
@@ -401,7 +409,7 @@ function connectSSE() {
 
   eventSource.addEventListener('round_end', (e) => {
     try {
-      handleRoundEnd(JSON.parse(e.data))
+      handleRoundEnd(JSON.parse(e.data)).catch(() => {})
     } catch (err) {
       console.warn('[FightPage] SSE round_end failed:', err)
     }
@@ -409,7 +417,7 @@ function connectSSE() {
 
   eventSource.addEventListener('fight_end', (e) => {
     try {
-      handleFightEnd(JSON.parse(e.data))
+      handleFightEnd(JSON.parse(e.data)).catch(() => {})
     } catch (err) {
       console.warn('[FightPage] SSE fight_end failed:', err)
     }
@@ -660,6 +668,7 @@ onMounted(async () => {
 })
 
 onUnmounted(() => {
+  _pageDestroyed = true
   if (pollHandle) clearInterval(pollHandle)
   stopHumanPolling()
   disconnectSSE()