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/LeaderboardPage.vue

@@ -1,10 +1,13 @@
 <script setup lang="ts">
 import { ref, onMounted } from 'vue'
 import { RouterLink } from 'vue-router'
+import SpritePreview from '../components/SpritePreview.vue'
 
 interface Bot {
   id: string
   name: string
+  avatarSeed: string
+  archetype: string
   eloRating: number
   wins: number
   losses: number
@@ -50,7 +53,7 @@ const record = (b: Bot) => `${b.wins}W - ${b.losses}L`
       </div>
 
       <!-- Table -->
-      <div class="flex-1 min-h-0 overflow-y-auto border border-border rounded-lg bg-surface-raised/50 neon-border-purple">
+      <div class="flex-1 min-h-0 overflow-y-auto border border-border rounded-lg bg-surface-raised/50">
         <table class="w-full">
           <thead class="sticky top-0 bg-surface-raised z-10">
             <tr class="border-b border-border text-text-muted font-display text-[10px] uppercase tracking-[0.15em]">
@@ -73,8 +76,15 @@ const record = (b: Bot) => `${b.wins}W - ${b.losses}L`
                 {{ index + 1 }}
               </td>
               <td class="px-4 py-3">
-                <RouterLink :to="`/bot/${bot.name}`" class="hover:text-neon-cyan transition-colors">
-                  <span class="font-display font-bold text-sm tracking-wide text-text-primary">
+                <RouterLink :to="`/bot/${bot.name}`" class="flex items-center gap-2 hover:text-neon-cyan transition-colors">
+                  <SpritePreview
+                    :seed="bot.avatarSeed || bot.name"
+                    :archetype="bot.archetype || 'standard'"
+                    :tier="bot.tier"
+                    :size="24"
+                    class="shrink-0"
+                  />
+                  <span class="font-display font-bold text-sm tracking-wide text-text-primary truncate">
                     {{ bot.name }}
                   </span>
                 </RouterLink>