Jellyfin test server with music and Live TV (docs/testing.md, "Test server").

    scripts/test-server/up.sh     # media (first time), 3 live channels, Jellyfin on port 8097, set-up
    scripts/test-server/down.sh   # stops everything; data kept in ~/.local/share/playfin-testserver

Sign in as "playfin" / "playfin-test" (local test server only). Remove ~/.local/share/playfin-testserver to start
from scratch.
