refactor: tighten project structure and strengthen tooling

src/utils/Time.ts

@@ -1 +1,42 @@
-// src/utils/Time.ts
+type TickListener = (delta: number, elapsed: number) => void;
+
+export class Time {
+  private readonly listeners = new Set<TickListener>();
+  private animationFrameId = 0;
+  private lastTick = performance.now();
+  private elapsed = 0;
+
+  constructor() {
+    this.tick = this.tick.bind(this);
+    this.animationFrameId = window.requestAnimationFrame(this.tick);
+  }
+
+  subscribe(listener: TickListener): () => void {
+    this.listeners.add(listener);
+
+    return () => {
+      this.listeners.delete(listener);
+    };
+  }
+
+  getElapsed(): number {
+    return this.elapsed;
+  }
+
+  destroy(): void {
+    window.cancelAnimationFrame(this.animationFrameId);
+    this.listeners.clear();
+  }
+
+  private tick(now: number): void {
+    const delta = (now - this.lastTick) / 1000;
+    this.lastTick = now;
+    this.elapsed += delta;
+
+    this.listeners.forEach((listener) => {
+      listener(delta, this.elapsed);
+    });
+
+    this.animationFrameId = window.requestAnimationFrame(this.tick);
+  }
+}