perf(ui): split right panel and secondary viewer chunks (#239)

## Summary
- split the right panel, picker, and tool call secondary viewers into
smaller deferred chunks
- release hidden right-panel file buffers and stop tracking static
tool-call scrollers when they are not needed
- keep this branch focused on the remaining secondary viewer chunking
work now that the Monaco-specific chunking moved into PR 215

## Testing
- npm run build --workspace @codenomad/ui

packages/ui/src/components/tool-call.tsx

@@ -514,6 +514,7 @@ function ToolCallDetails(props: {
   })
 
   const { renderDiffContent } = createDiffContentRenderer({
+    toolState: props.toolState,
     preferences: props.preferences,
     setDiffViewMode: props.setDiffViewMode,
     isDark: props.isDark,