release: v0.2.0 — TypeScript 源码重构

### Changed
- 全部源码从 JavaScript 迁移到 TypeScript (strict mode)
- core.js (1244行) 拆分为 toast.ts + api.ts + templates.ts
- 删除手动维护的 types/index.d.ts，类型从源码自动生成
- 构建工具链: Babel → ts-jest, 新增 @rollup/plugin-typescript
- 新增 rollup-plugin-dts 生成合并 .d.ts

### Added
- tsconfig.json (strict: true)
- src/types.ts 核心类型模块 (39 个导出类型)
- .eslintrc.json (@typescript-eslint)
- .gitea/workflows/ci.yml (Node 18/20/22/24 矩阵)
- CHANGELOG.md

### Aligned with metona-starter
- package.json: type:module, engines≥16, prepublishOnly
- rollup.config.js: dts plugin, port 3001
- jest.config.cjs, build.sh, serve.sh, .gitignore (.npmrc)

### Removed
- babel.config.js, types/ 目录, 所有 src/*.js

src/utils.ts

@@ -0,0 +1,40 @@
+/**
+ * MetonaToast Utils — 工具函数
+ * @module utils
+ * @version 0.2.0
+ */
+
+/**
+ * 生成唯一ID
+ */
+export const generateId = (): string => {
+  return 'met-' + Date.now().toString(36) + '-' + Math.random().toString(36).slice(2, 8);
+};
+
+/**
+ * HTML转义
+ * @param s - 输入字符串
+ */
+export const escapeHTML = (s: string | null | undefined): string => {
+  if (typeof document === 'undefined') {
+    return String(s == null ? '' : s)
+      .replace(/&/g, '&')
+      .replace(/</g, '&lt;')
+      .replace(/>/g, '&gt;')
+      .replace(/"/g, '&quot;')
+      .replace(/'/g, '&#039;');
+  }
+
+  const div = document.createElement('div');
+  div.textContent = String(s == null ? '' : s);
+  return div.innerHTML;
+};
+
+/**
+ * 检测暗色模式偏好
+ */
+export const prefersDark = (): boolean => {
+  return typeof window !== 'undefined' &&
+    typeof window.matchMedia === 'function' &&
+    window.matchMedia('(prefers-color-scheme: dark)').matches;
+};