feat(timer): 添加定时器和冷却系统 (#325)

- 添加 ITimerService 接口和 TimerService 实现
- 支持一次性定时器和重复定时器
- 支持冷却系统 (startCooldown/isCooldownReady/getCooldownProgress)
- 添加 8 个蓝图节点:
  - StartCooldown, IsCooldownReady, GetCooldownProgress
  - ResetCooldown, GetCooldownInfo
  - HasTimer, CancelTimer, GetTimerRemaining

packages/timer/tsconfig.build.json

@@ -0,0 +1,22 @@
+{
+    "compilerOptions": {
+        "target": "ES2020",
+        "module": "ES2020",
+        "moduleResolution": "bundler",
+        "lib": ["ES2020", "DOM"],
+        "outDir": "./dist",
+        "rootDir": "./src",
+        "strict": true,
+        "esModuleInterop": true,
+        "allowSyntheticDefaultImports": true,
+        "skipLibCheck": true,
+        "forceConsistentCasingInFileNames": true,
+        "declaration": true,
+        "declarationMap": true,
+        "resolveJsonModule": true,
+        "experimentalDecorators": true,
+        "emitDecoratorMetadata": true
+    },
+    "include": ["src/**/*"],
+    "exclude": ["node_modules", "dist"]
+}