perf: NPC 생명주기 메모리 프로파일과 큐 정리를 추가한다

app/game-engine/test/npcLifecycleMemoryProfiler.test.ts

@@ -0,0 +1,20 @@
+import { describe, expect, it } from 'vitest';
+
+import { linearRegressionSlope } from './helpers/npcLifecycleMemoryProfiler.js';
+
+describe('NPC lifecycle memory profiler metrics', () => {
+    it('calculates the retained-byte slope from unevenly spaced samples', () => {
+        expect(
+            linearRegressionSlope([
+                { x: 0, y: 100 },
+                { x: 2, y: 140 },
+                { x: 5, y: 200 },
+            ])
+        ).toBeCloseTo(20, 8);
+    });
+
+    it('returns zero when a trend cannot be established', () => {
+        expect(linearRegressionSlope([])).toBe(0);
+        expect(linearRegressionSlope([{ x: 1, y: 10 }])).toBe(0);
+    });
+});