Add explicit useEffect to sync height on value changes

- Ensures syncDisplayHeight runs whenever value prop changes
- Fixes issue where height wasn't recalculating on text deletion
- Complements existing ResizeObserver with direct value monitoring

ui/desktop/src/components/RichChatInput.tsx

@@ -1006,6 +1006,12 @@ export const RichChatInput = forwardRef<RichChatInputRef, RichChatInputProps>(({
     const cleanup = monitorTextareaChanges();
     return cleanup;
   }, [monitorTextareaChanges]);
+
+  // Explicitly sync height whenever value changes (including when text is deleted)
+  useEffect(() => {
+    syncDisplayHeight();
+    ensureStyleConsistency();
+  }, [value, syncDisplayHeight, ensureStyleConsistency]);
   // Tooltip handlers
   const handleSuggestionSelect = useCallback((suggestion: string) => {
     const newValue = value.slice(0, tooltip.wordStart) +