[UI] Optimize bundle (#11896)

* lazy load global window modules

- Required for plugins
- Can be separated from the "main.tsx" code

Co-authored-by: Copilot <copilot@github.com>

* Defer modal loading

Co-authored-by: Copilot <copilot@github.com>

* Rollup visualiser tool

* Remove debug msg

* Rearrange to reduce deltas

* Refactor CodeEditor and PdfPreview

* Split NotesPanel

Co-authored-by: Copilot <copilot@github.com>

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Co-authored-by: Copilot <copilot@github.com>

src/frontend/vite.config.ts

@@ -3,6 +3,7 @@ import { codecovVitePlugin } from '@codecov/vite-plugin';
 import { vanillaExtractPlugin } from '@vanilla-extract/vite-plugin';
 import react from '@vitejs/plugin-react';
 import license from 'rollup-plugin-license';
+import { visualizer } from 'rollup-plugin-visualizer';
 import { defineConfig } from 'vite';
 import istanbul from 'vite-plugin-istanbul';
 
@@ -26,6 +27,7 @@ export default defineConfig(({ command, mode }) => {
 
   return {
     plugins: [
+      visualizer(),
       react({
         babel: {
           plugins: ['macros']