feat: update pnpm workspace and dependencies, migrate to tsdown for builds

core/platform/tsdown.config.ts

@@ -0,0 +1,12 @@
+import { defineConfig } from 'tsdown';
+
+export default defineConfig({
+  entry: {
+    browsers: 'src/browsers/index.ts',
+    multi: 'src/multi/index.ts',
+  },
+  format: ['esm', 'cjs'],
+  dts: true,
+  clean: true,
+  hash: false,
+});