- **Android Auto, half-built.** Round forty-eight put the card on
  `androidx.media3` — a `MediaSessionService` over a `SimpleBasePlayer` —
  which is the base a browsable service needs and the reason that round
  happened at all. What is missing is the browse tree: `MediaService` becomes
  a `MediaLibraryService`, `onGetLibraryRoot` and `onGetChildren` answer with
  the library's own shape, an `automotive_app_desc.xml` and its
  `<meta-data>` declare the app to Auto, and a tapped queue row maps back
  through `queueBase` to `playQueueAt()` (which is why
  `COMMAND_SET_MEDIA_ITEM` and its neighbours are deliberately NOT advertised
  yet). None of it can be walked from here: Auto needs the Desktop Head Unit
  or a car.