Summary

Fixes rapid flickering/redraw when viewing the prompt preview pane (Shift+O).

Root Cause

The useEffect that generates prompt previews depended on displayedTasks and iterations arrays:

useEffect(() => {
  const effectiveTaskId = displayedTasks[selectedIndex]?.id;
  setPromptPreview('Generating...');  // ← triggers re-render
  // ...
}, [displayedTasks, iterations, ...]);  // ← unstable array refs

If these arrays get new references (common in React), the effect fires repeatedly, calling setPromptPreview which triggers another render → infinite loop.

Fix

Extract the task ID into a memoized value, then depend on that stable string:

const promptPreviewTaskId = useMemo(() => 
  displayedTasks[selectedIndex]?.id,
  [displayedTasks, selectedIndex]
);

useEffect(() => {
  // ...
}, [promptPreviewTaskId, ...]);  // ← stable string, only changes on actual selection change

Test plan

• Open prompt preview with Shift+O - no flickering
• Switch between tasks - preview updates correctly
• Switch between tasks/iterations views - preview updates correctly

Summary by CodeRabbit

Release Notes

• Performance Improvements
  • Enhanced prompt preview feature stability with optimised refresh logic to minimise unnecessary re-renders and data fetches.