fix: selective leaderboard cache invalidation instead of full clear (BUG-S10)

Only invalidates __alltime__ and current season cache keys on fight completion,
preserving historical season caches. Test verifies selective behavior.

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

server/src/engine/orchestrator.ts

@@ -577,8 +577,9 @@ async function executeFightRounds(fightId: string, botA: BotRecord, botB: BotRec
     trackMetric(`challenge_${ct}`)
   }
 
-  // Invalidate leaderboard cache after Elo/stats update
+  // Invalidate leaderboard cache — selective: only alltime + current season
-  invalidateLeaderboardCache()
+  const currentSeason = getCurrentSeason()
+  invalidateLeaderboardCache(currentSeason?.id)
 
   // Advance tournament bracket if this was a tournament match
   try { onTournamentFightFinished(fightId, winnerId ?? null) } catch { /* not a tournament fight */ }

server/src/routes/bots-cache.test.ts

@@ -0,0 +1,102 @@
+import { describe, it, expect, vi, beforeEach } from 'vitest'
+
+// Mock DB and dependencies to import bots module
+vi.mock('../db/index.js', () => ({
+  db: {
+    select: vi.fn().mockReturnValue({
+      from: vi.fn().mockReturnValue({
+        where: vi.fn().mockReturnValue({
+          limit: vi.fn().mockResolvedValue([]),
+        }),
+      }),
+    }),
+  },
+  schema: {
+    bots: { id: 'id', name: 'name', publicKey: 'publicKey', eloRating: 'eloRating', wins: 'wins', losses: 'losses', winStreak: 'winStreak', tier: 'tier', avatarSeed: 'avatarSeed', archetype: 'archetype', botType: 'botType', hasWallet: 'hasWallet', zapsReceived: 'zapsReceived', isActive: 'isActive', webhookUrl: 'webhookUrl', secretHash: 'secretHash', bestStreak: 'bestStreak', satsWagered: 'satsWagered' },
+    walletConnections: { id: 'id', botId: 'botId' },
+  },
+}))
+
+vi.mock('../engine/scoring.js', () => ({
+  TIER_NAMES: ['Baby', 'Bronze', 'Silver', 'Gold', 'Platinum', 'Diamond', 'Legend'],
+  TIER_COLORS: ['#999', '#cd7f32', '#c0c0c0', '#ffd700', '#e5e4e2', '#b9f2ff', '#ff6b6b'],
+}))
+
+vi.mock('../engine/achievements.js', () => ({
+  computeAchievements: vi.fn().mockReturnValue([]),
+}))
+
+vi.mock('../engine/orchestrator.js', () => ({
+  isAllowedWebhookUrl: vi.fn().mockReturnValue(true),
+}))
+
+vi.mock('../engine/webhook-test.js', () => ({
+  testWebhook: vi.fn().mockResolvedValue({ success: true }),
+}))
+
+vi.mock('../middleware/rate-limit.js', () => ({
+  rateLimit: () => async (_c: any, next: any) => next(),
+}))
+
+const { invalidateLeaderboardCache, _leaderboardCache } = await import('./bots.js')
+
+describe('leaderboard cache selective invalidation', () => {
+  beforeEach(() => {
+    _leaderboardCache.clear()
+  })
+
+  it('invalidates __alltime__ and current but preserves historical season', () => {
+    const now = Date.now()
+    _leaderboardCache.set('__alltime__', { data: 'alltime', expiresAt: now + 30_000 })
+    _leaderboardCache.set('current', { data: 'current-season', expiresAt: now + 30_000 })
+    _leaderboardCache.set('s1', { data: 'season-1-history', expiresAt: now + 30_000 })
+    _leaderboardCache.set('s2', { data: 'season-2-history', expiresAt: now + 30_000 })
+
+    invalidateLeaderboardCache()
+
+    expect(_leaderboardCache.has('__alltime__')).toBe(false)
+    expect(_leaderboardCache.has('current')).toBe(false)
+    // Historical seasons preserved
+    expect(_leaderboardCache.has('s1')).toBe(true)
+    expect(_leaderboardCache.has('s2')).toBe(true)
+  })
+
+  it('also invalidates specific season when seasonId passed', () => {
+    const now = Date.now()
+    _leaderboardCache.set('__alltime__', { data: 'alltime', expiresAt: now + 30_000 })
+    _leaderboardCache.set('current', { data: 'current', expiresAt: now + 30_000 })
+    _leaderboardCache.set('s1', { data: 'season-1', expiresAt: now + 30_000 })
+    _leaderboardCache.set('s2', { data: 'season-2', expiresAt: now + 30_000 })
+
+    invalidateLeaderboardCache('s1')
+
+    expect(_leaderboardCache.has('__alltime__')).toBe(false)
+    expect(_leaderboardCache.has('current')).toBe(false)
+    expect(_leaderboardCache.has('s1')).toBe(false)
+    // Other seasons preserved
+    expect(_leaderboardCache.has('s2')).toBe(true)
+  })
+
+  it('no-op on empty cache', () => {
+    expect(_leaderboardCache.size).toBe(0)
+    invalidateLeaderboardCache()
+    expect(_leaderboardCache.size).toBe(0)
+  })
+
+  it('only removes targeted keys, leaves other entries', () => {
+    const now = Date.now()
+    // 5 cached entries
+    _leaderboardCache.set('__alltime__', { data: 'a', expiresAt: now + 30_000 })
+    _leaderboardCache.set('current', { data: 'c', expiresAt: now + 30_000 })
+    _leaderboardCache.set('s1', { data: '1', expiresAt: now + 30_000 })
+    _leaderboardCache.set('s2', { data: '2', expiresAt: now + 30_000 })
+    _leaderboardCache.set('s3', { data: '3', expiresAt: now + 30_000 })
+
+    invalidateLeaderboardCache('s2')
+
+    // Removed: __alltime__, current, s2
+    expect(_leaderboardCache.size).toBe(2)
+    expect(_leaderboardCache.has('s1')).toBe(true)
+    expect(_leaderboardCache.has('s3')).toBe(true)
+  })
+})

server/src/routes/bots.ts

@@ -15,10 +15,16 @@ export const botsRouter = new Hono()
 const leaderboardCache = new Map<string, { data: unknown; expiresAt: number }>()
 const LEADERBOARD_TTL_MS = 30_000 // 30s cache
 
-export function invalidateLeaderboardCache() {
+export function invalidateLeaderboardCache(seasonId?: string) {
-  leaderboardCache.clear()
+  // Selective: only clear active leaderboards, preserve historical season caches
+  leaderboardCache.delete('__alltime__')
+  leaderboardCache.delete('current')
+  if (seasonId) leaderboardCache.delete(seasonId)
 }
 
+// Expose cache for testing
+export const _leaderboardCache = leaderboardCache
+
 function hashSecret(secret: string): string {
   return createHash('sha256').update(secret).digest('hex')
 }