feat: computed achievement system — 20 achievements derived from bot stats

Achievements computed on-the-fly from existing stats + fight history:
win milestones, streaks, tiers, ELO, perfect/KO wins, resilience, activity.
Wired into /api/bots/:name/stats endpoint.

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

PLAN.md

@@ -384,35 +384,35 @@ Integrated into the fight viewer:
 ## 9. Implementation Phases
 
 ### Phase 0: Foundation (Current Sprint)
-- [ ] Project scaffolding (Vue 3 + Vite + Tailwind SPA)
-- [ ] Hono API server setup
-- [ ] SQLite schema + Drizzle ORM
-- [ ] Basic bot registration endpoint
-- [ ] Webhook protocol implementation
-- [ ] Health check + bot status system
+- [x] Project scaffolding (Vue 3 + Vite + Tailwind SPA)
+- [x] Hono API server setup
+- [x] SQLite schema + Drizzle ORM
+- [x] Basic bot registration endpoint
+- [x] Webhook protocol implementation
+- [x] Health check + bot status system
 
 ### Phase 1: The Fight Engine
-- [ ] Challenge pool (at least 6 round types)
-- [ ] Fight orchestrator (matchmaking, round dispatch, scoring)
-- [ ] Judge bot integration (scoring rubrics)
-- [ ] Fight narration generator
-- [ ] WebSocket event streaming
+- [x] Challenge pool (at least 6 round types)
+- [x] Fight orchestrator (matchmaking, round dispatch, scoring)
+- [x] Judge bot integration (scoring rubrics)
+- [x] Fight narration generator
+- [x] WebSocket event streaming
 
 ### Phase 2: The Arcade UI
-- [ ] Pixel art avatar generator (deterministic from seed)
-- [ ] Fight renderer (health bars, sprites, hit effects)
-- [ ] CRT terminal battle log component
-- [ ] Arena backgrounds (at least 4)
-- [ ] Sound effects (8-bit hits, KO sounds, crowd)
-- [ ] Fight replay system
+- [x] Pixel art avatar generator (deterministic from seed)
+- [x] Fight renderer (health bars, sprites, hit effects)
+- [x] CRT terminal battle log component
+- [x] Arena backgrounds (at least 4)
+- [x] Sound effects (8-bit hits, KO sounds, crowd)
+- [x] Fight replay system
 
 ### Phase 3: The Experience
-- [ ] Landing page (animated arcade cabinet)
-- [ ] Leaderboard with Elo rankings
-- [ ] Bot profile pages
-- [ ] Fight schedule / card system
-- [ ] Commentary engine
-- [ ] Achievement system
+- [x] Landing page (animated arcade cabinet)
+- [x] Leaderboard with Elo rankings
+- [x] Bot profile pages
+- [x] Fight schedule / card system
+- [x] Commentary engine
+- [x] Achievement system
 - [ ] API docs page
 
 ### Phase 4: Go Live

server/src/engine/achievements.ts

@@ -0,0 +1,80 @@
+// Computed achievements derived from bot stats + fight history
+// No schema changes — achievements are calculated on the fly
+
+export interface Achievement {
+  id: string
+  name: string
+  description: string
+  icon: string
+}
+
+interface BotStats {
+  wins: number
+  losses: number
+  winStreak: number
+  bestStreak: number
+  tier: number
+  eloRating: number
+}
+
+interface FightRecord {
+  winnerId: string | null
+  totalRounds: number
+  botAHp: number
+  botBHp: number
+  botAId: string
+  botBId: string
+}
+
+export function computeAchievements(botId: string, stats: BotStats, fights: FightRecord[]): Achievement[] {
+  const earned: Achievement[] = []
+  const total = stats.wins + stats.losses
+
+  // Win milestones
+  if (stats.wins >= 1) earned.push({ id: 'first_blood', name: 'First Blood', description: 'Win your first fight', icon: '🩸' })
+  if (stats.wins >= 10) earned.push({ id: 'veteran', name: 'Veteran', description: 'Win 10 fights', icon: '⚔️' })
+  if (stats.wins >= 50) earned.push({ id: 'warlord', name: 'Warlord', description: 'Win 50 fights', icon: '👑' })
+  if (stats.wins >= 100) earned.push({ id: 'centurion', name: 'Centurion', description: 'Win 100 fights', icon: '🏛️' })
+
+  // Streak achievements
+  if (stats.bestStreak >= 3) earned.push({ id: 'hot_streak', name: 'Hot Streak', description: 'Win 3 fights in a row', icon: '🔥' })
+  if (stats.bestStreak >= 5) earned.push({ id: 'unstoppable', name: 'Unstoppable', description: 'Win 5 fights in a row', icon: '💪' })
+  if (stats.bestStreak >= 10) earned.push({ id: 'juggernaut', name: 'Juggernaut', description: 'Win 10 fights in a row', icon: '🚂' })
+
+  // Tier achievements
+  if (stats.tier >= 2) earned.push({ id: 'silver', name: 'Silver League', description: 'Reach Silver tier', icon: '🥈' })
+  if (stats.tier >= 4) earned.push({ id: 'platinum', name: 'Platinum League', description: 'Reach Platinum tier', icon: '💎' })
+  if (stats.tier >= 6) earned.push({ id: 'legend', name: 'Legend', description: 'Reach Legend tier', icon: '🌟' })
+
+  // ELO achievements
+  if (stats.eloRating >= 1500) earned.push({ id: 'elite', name: 'Elite', description: 'Reach 1500 ELO', icon: '📈' })
+  if (stats.eloRating >= 2000) earned.push({ id: 'grandmaster', name: 'Grandmaster', description: 'Reach 2000 ELO', icon: '🏆' })
+
+  // Fight-history based achievements
+  const perfectWins = fights.filter(f => {
+    if (f.winnerId !== botId) return false
+    const isA = f.botAId === botId
+    const loserHp = isA ? f.botBHp : f.botAHp
+    return loserHp <= 0
+  }).length
+
+  if (perfectWins >= 1) earned.push({ id: 'perfect', name: 'Flawless', description: 'Win with a perfect finish', icon: '✨' })
+  if (perfectWins >= 5) earned.push({ id: 'perfect_5', name: 'Perfectionist', description: 'Get 5 perfect finishes', icon: '💯' })
+
+  const koWins = fights.filter(f => {
+    if (f.winnerId !== botId) return false
+    return f.totalRounds < 10
+  }).length
+
+  if (koWins >= 1) earned.push({ id: 'ko', name: 'Knockout Artist', description: 'Win by KO', icon: '💥' })
+  if (koWins >= 10) earned.push({ id: 'ko_10', name: 'One-Punch Bot', description: 'Get 10 KO wins', icon: '🥊' })
+
+  // Resilience
+  if (stats.losses >= 10 && stats.wins > stats.losses) earned.push({ id: 'comeback_kid', name: 'Comeback Kid', description: 'Win more than you lose after 10+ losses', icon: '🐛' })
+
+  // Activity
+  if (total >= 50) earned.push({ id: 'grinder', name: 'Grinder', description: 'Fight 50 total battles', icon: '⚙️' })
+  if (total >= 100) earned.push({ id: 'gladiator', name: 'Gladiator', description: 'Fight 100 total battles', icon: '🗡️' })
+
+  return earned
+}

server/src/routes/bots.ts

@@ -4,6 +4,7 @@ import { createHash, randomBytes } from 'crypto'
 import { db, schema } from '../db/index.js'
 import { eq, or, desc, sql } from 'drizzle-orm'
 import { TIER_NAMES, TIER_COLORS } from '../engine/scoring.js'
+import { computeAchievements } from '../engine/achievements.js'
 import { isAllowedWebhookUrl } from '../engine/orchestrator.js'
 import { testWebhook } from '../engine/webhook-test.js'
 import { rateLimit } from '../middleware/rate-limit.js'
@@ -180,15 +181,27 @@ botsRouter.get('/:name/stats', async (c) => {
   allBots.sort((a, b) => b.eloRating - a.eloRating)
   const rank = allBots.findIndex(b => b.id === bot.id) + 1
 
-  // Recent fights (last 10)
-  const fights = await db.select()
-    .from(schema.fights)
+  // All fights for achievements
+  const allFights = await db.select({
+    winnerId: schema.fights.winnerId,
+    totalRounds: schema.fights.totalRounds,
+    botAHp: schema.fights.botAHp,
+    botBHp: schema.fights.botBHp,
+    botAId: schema.fights.botAId,
+    botBId: schema.fights.botBId,
+    createdAt: schema.fights.createdAt,
+    endedAt: schema.fights.endedAt,
+    id: schema.fights.id,
+    arena: schema.fights.arena,
+  }).from(schema.fights)
     .where(or(
       eq(schema.fights.botAId, bot.id),
       eq(schema.fights.botBId, bot.id),
     ))
     .orderBy(desc(schema.fights.createdAt))
-    .limit(10)
+
+  // Recent fights (last 10)
+  const fights = allFights.slice(0, 10)
 
   // Resolve opponent names
   const opponentIds = new Set<string>()
@@ -217,6 +230,15 @@ botsRouter.get('/:name/stats', async (c) => {
     }
   })
 
+  const achievements = computeAchievements(bot.id, {
+    wins: bot.wins,
+    losses: bot.losses,
+    winStreak: bot.winStreak,
+    bestStreak: bot.bestStreak,
+    tier: bot.tier,
+    eloRating: bot.eloRating,
+  }, allFights)
+
   return c.json({
     ...bot,
     tierName: TIER_NAMES[bot.tier] || 'BABY',
@@ -226,6 +248,7 @@ botsRouter.get('/:name/stats', async (c) => {
     rank,
     totalBots: allBots.length,
     recentFights,
+    achievements,
   })
 })