test: add static analysis tests for memory leak destroy contracts

Verifies FightScene.destroy(), FightViewer.vue onUnmounted, and audio
module cleanup invariants via source-code scanning — ensures future
changes don't silently break resource cleanup.

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

frontend/src/game/__tests__/memory-audit.test.ts

@@ -0,0 +1,107 @@
+import { describe, it, expect } from 'vitest'
+import { readFileSync } from 'fs'
+import { resolve, dirname } from 'path'
+
+const gameDir = resolve(dirname(import.meta.url.replace('file://', '')), '..')
+const readGame = (rel: string) => readFileSync(resolve(gameDir, rel), 'utf-8')
+
+describe('memory leak audit — static analysis', () => {
+  describe('FightScene.destroy() cleanup contract', () => {
+    const src = readGame('FightScene.ts')
+
+    it('stops music', () => {
+      expect(src).toContain('stopMusic()')
+    })
+
+    it('stops talking animations', () => {
+      expect(src).toContain("stopTalking('a')")
+      expect(src).toContain("stopTalking('b')")
+    })
+
+    it('clears speech bubble arrays', () => {
+      expect(src).toContain('activeBubbleA.length = 0')
+      expect(src).toContain('activeBubbleB.length = 0')
+    })
+
+    it('clears tracked timers', () => {
+      expect(src).toContain('cleanupTimers.clear()')
+    })
+
+    it('clears audio timers', () => {
+      expect(src).toContain('clearAllAudioTimers()')
+    })
+
+    it('destroys all Kaplay objects', () => {
+      expect(src).toMatch(/k\.get\('\*'\)\.forEach/)
+    })
+
+    it('quits Kaplay engine', () => {
+      expect(src).toContain('k.quit()')
+    })
+  })
+
+  describe('FightViewer.vue cleanup in onUnmounted', () => {
+    const src = readGame('../components/FightViewer.vue')
+
+    it('calls scene.destroy()', () => {
+      expect(src).toContain('scene.destroy()')
+    })
+
+    it('nullifies scene reference', () => {
+      expect(src).toContain('scene = null')
+    })
+
+    it('calls stopAllAudio()', () => {
+      expect(src).toContain('stopAllAudio()')
+    })
+
+    it('removes canvas webglcontextlost listener', () => {
+      expect(src).toContain("removeEventListener('webglcontextlost'")
+    })
+
+    it('removes canvas webglcontextrestored listener', () => {
+      expect(src).toContain("removeEventListener('webglcontextrestored'")
+    })
+
+    it('nullifies canvas handler references', () => {
+      expect(src).toContain('canvasContextLostHandler = null')
+      expect(src).toContain('canvasContextRestoredHandler = null')
+    })
+
+    it('clears cleanup timer handles', () => {
+      expect(src).toMatch(/clearTimeout\(cleanupTimerHandle\)/)
+    })
+
+    it('cancels speechSynthesis', () => {
+      expect(src).toContain('speechSynthesis.cancel()')
+    })
+  })
+
+  describe('audio module does not leak per-scene resources', () => {
+    it('audioTimeout cleanup function exists', () => {
+      const ctx = readGame('audio/context.ts')
+      expect(ctx).toContain('export function clearAllAudioTimers()')
+    })
+
+    it('TTS cache has bounded size (MAX_CACHE)', () => {
+      const tts = readGame('tts.ts')
+      expect(tts).toMatch(/const MAX_CACHE\s*=\s*\d+/)
+    })
+
+    it('TTS cache uses LRU eviction', () => {
+      const tts = readGame('tts.ts')
+      expect(tts).toContain('lastAccess')
+      expect(tts).toMatch(/lruKey|lruTime/)
+    })
+
+    it('kokoroClearCache export exists', () => {
+      const tts = readGame('tts.ts')
+      expect(tts).toContain('export function kokoroClearCache()')
+    })
+
+    it('kokoroStop export exists', () => {
+      const tts = readGame('tts.ts')
+      expect(tts).toContain('export function kokoroStop()')
+    })
+  })
+})