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

tsconfig.json

@@ -0,0 +1,24 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "ES2020",
+    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "moduleResolution": "bundler",
+    "strict": true,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "skipLibCheck": true,
+    "declaration": false,
+    "declarationMap": false,
+    "sourceMap": true,
+    "outDir": "dist",
+    "rootDir": "src",
+    "baseUrl": ".",
+    "resolveJsonModule": true,
+    "isolatedModules": true
+  },
+  "include": ["src/**/*.ts"],
+  "exclude": ["node_modules", "dist", "tests", "site"]
+}