fix bad fallback logic external editor logic (google-gemini#17166)

Author: scidomino

packages/cli/src/ui/components/shared/text-buffer.ts

@@ -2242,11 +2242,9 @@ export function useTextBuffer({
 
     if (!command) {
       command =
-        (process.env['VISUAL'] ??
+        process.env['VISUAL'] ??
         process.env['EDITOR'] ??
-        process.platform === 'win32')
-          ? 'notepad'
-          : 'vi';
+        (process.platform === 'win32' ? 'notepad' : 'vi');
     }
 
     dispatch({ type: 'create_undo_snapshot' });