fix: prioritize ESM build in package exports to fix webpack warnings (#481)

Updates package.json exports to default to the ESM build instead of CommonJS,
resolving "Critical dependency: the request of a dependency is an expression"
warnings in webpack builds.

Changes:
- Set "default" to ESM build (./dist/module/) preserving native import()
- Add explicit "import" condition for ESM-aware bundlers
- Add "types" condition for better TypeScript resolution
- Keep "require" pointing to CommonJS for Node.js compatibility

Tested on Next.js v15 with webpack (non-turbopack). Previous workaround required
manual webpack config:

```js
webpack: (config) => {
  config.resolve.mainFields = ['browser', 'module', 'main'];
  config.resolve.conditionNames = ['browser', 'module', 'import', 'default'];
  return config;
}
```

This exports change eliminates the need for manual webpack configuration
by making bundlers prefer the ES2020 build that preserves dynamic imports.

Fixes: webpack "Critical dependency" warnings in issue #1437

Author: nasatome

package.json

@@ -65,8 +65,11 @@
   },
   "exports": {
     ".": {
-      "node":"./dist/main/index.js",
-      "browser": "./dist/module/index.js",
+      "types": "./dist/module/index.d.ts",
+      "import": "./dist/module/index.js",
+      "browser": "./dist/module/index.js", 
+      "require": "./dist/main/index.js",
+      "node": "./dist/main/index.js",
       "default": "./dist/main/index.js"
     },
     "./websocket": {