* feat: KDE desktop as a bottom-screen mode beside the top-screen session
* test: bottom-desktop launch test sets DISPLAY instead of inheriting it
* fix: drop the bottom desktop's launch when the session stops while preparing it
* fix: bottom desktop restarts on a fresh surface, trackpad/touch toggle, loading throbber, DroidDeck's display driver
* fix: bottom desktop pauses with the session and opens the keyboard for a tapped text field
* fix: no bottom desktop guest starts or keeps running unfrozen while the session is paused
* fix: bottom desktop treats a freeze in progress as paused
* fix: only the session that began a freeze clears its pausing flag
* fix: bottom desktop launch is stored and cleared only for its own session generation
* fix: a stopped session tears down the bottom desktop it started even after a newer launch is prepared
* fix: a new session's bottom desktop replaces one an earlier session left running
* fix: release the bottom desktop's keyboard watcher when its compositor dies
* fix: bottom desktop starts its guest only for the launch its compositor was attached for
* fix: bottom desktop ignores compositor replies to an earlier session's attach