fix(app): fix CommandText console warnings (#15856)

Explicitly handle the null command case to prevent warnings. The intention of useCommandTextString after #15708 is to support null commands, so this change genuinely implements the desired behavior.

app/src/molecules/Command/hooks/useCommandTextString/index.tsx

@@ -216,6 +216,7 @@ export function useCommandTextString(
         commandText: utils.getCustomCommandText({ ...fullParams, command }),
       }
 
+    case undefined:
     case null:
       return { commandText: '' }