comma four: no engage/disengage sound

> No sound on engage/disengage on my car here: https://connect.comma.ai/4068b866e665273f/000000d8--128ce24e16/90/191
> Sound comes back later in the drive. Have had this failure before on my car, but can't find the routes

```
4068b866e665273f/000000d8--128ce24e16/90/191
```

Start by opening the linked connect.comma.ai route and reviewing the reported drive segment for the missing engage/disengage sound. Compare it with the later portion where sound returns and determine whether the failure can be reproduced; done means identifying a clear cause and confirming the sound behavior is restored without regression.

Written by the indexing model from the issue text.