fix: pdf.worker at root, drop vite-plugin-top-level-await package

Replace broken vite-plugin-static-copy target for pdf.worker with a
custom closeBundle plugin that copies the file directly to dist root.
Also uninstall vite-plugin-top-level-await which was removed from
vite.config.js in the previous commit.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

vite.config.js

@@ -17,11 +17,6 @@ const copyFiles = {
       src: 'node_modules/@element-hq/element-call-embedded/dist/*',
       dest: 'public/element-call',
     },
-    {
-      src: 'node_modules/pdfjs-dist/build/pdf.worker.min.mjs',
-      dest: '',
-      rename: 'pdf.worker.min.js',
-    },
     {
       src: 'config.json',
       dest: '',
@@ -41,6 +36,17 @@ const copyFiles = {
   ],
 };
 
+function copyPdfWorker() {
+  return {
+    name: 'copy-pdf-worker',
+    closeBundle() {
+      const src = path.resolve('node_modules/pdfjs-dist/build/pdf.worker.min.mjs');
+      const dest = path.resolve('dist/pdf.worker.min.js');
+      if (fs.existsSync(src)) fs.copyFileSync(src, dest);
+    },
+  };
+}
+
 function serverMatrixSdkCryptoWasm(wasmFilePath) {
   return {
     name: 'vite-plugin-serve-matrix-sdk-crypto-wasm',
@@ -87,6 +93,7 @@ export default defineConfig({
     vanillaExtractPlugin(),
     wasm(),
     react(),
+    copyPdfWorker(),
     ...(process.env.SENTRY_AUTH_TOKEN
       ? [
           sentryVitePlugin({