Replace tsup with tsdown (#28)

* refactor: replace tsup with tsdown for build configuration

- Added a new configuration file `tsdown.config.js` to manage the build process using tsdown.
- Removed the old `tsup.config.js` file as part of the migration to tsdown.
- Updated build options to include sourcemaps, cleaning, and TypeScript declaration file generation.
- Configured output formats for CommonJS, ES Module, and IIFE with appropriate settings.

* fix: update node engine requirement to >=22.12.0

Author: formfcw

package.json

@@ -45,8 +45,8 @@
 		"dist"
 	],
 	"scripts": {
-		"dev": "NODE_ENV=development tsup",
-		"build": "NODE_ENV=production tsup",
+		"dev": "NODE_ENV=development tsdown",
+		"build": "NODE_ENV=production tsdown",
 		"test": "vitest --typecheck --watch=false"
 	},
 	"dependencies": {
@@ -60,14 +60,14 @@
 		"eslint-plugin-vue": "10.7.0",
 		"globals": "17.3.0",
 		"prettier": "3.8.1",
-		"tsup": "8.5.1",
+		"tsdown": "0.20.1",
 		"typescript": "5.9.3",
 		"typescript-eslint": "8.54.0",
 		"vitest": "4.0.18",
 		"vue-eslint-parser": "10.2.0"
 	},
 	"engines": {
-		"node": ">=22"
+		"node": ">=22.12.0"
 	},
 	"packageManager": "[email protected]",
 	"pnpm": {