Show server backend (Jellyfin/Subsonic) in header and Settings list
The header now carries a "◈ Jellyfin" / "≋ Subsonic" badge for the
active server, and each row in the Settings server list shows its
backend between the name and URL — so it's obvious at a glance which
kind the current/other servers speak.
Also adds a getStarred2 deserialization regression test covering the
real-world response shape (status key after the payload, starred
artists present but dropped).