Focus chrome was implemented twice, once in the focusable wrapper and once
in the focus builders; both now go through FocusChrome. TvColorPicker's
channel row was a copy of TvNumberSpinner and is now that widget in compact
density.
Also trims unused helpers and fields and simplifies the Jellyfin browse
paths.
Drops dead code across services, models, utils and widgets, including the
connection auth service, which had no implementer, and the Live TV DVR
provisioning models, which had no caller.
Tests that only covered deleted behaviour are removed or trimmed. No
behaviour change.
Un-gates music libraries; adds CardShape.square plumbing (circular
artists), artists/albums/tracks browse groupings with per-grouping
sorts, audio playlists tab, artist + album detail screens with dpad
track rows, music context-menu actions, and a stub MusicPlaybackService
seam for the upcoming engine.