The fixture answers /api/vessels without X-Feed-Source, so the source
fell back to the feed's name and the attribution check failed. Send
AISStream as the bundled server does.
The flight, military and vessel feeds were named after the providers the
bundled server uses (/api/opensky, /api/adsblol/mil, /api/ais-live and
their track routes; createOpenSkySource, createAdsbLolSource,
createAisStreamSource). Any server should be able to answer a feed from
its own provider, so the feeds are now:
/api/flights /api/flights/track?icao24=
/api/military /api/military/track?hex=
/api/vessels /api/vessels/track?mmsi=
with createFlightSource, createMilitarySource and createVesselSource. The
old routes are removed. Each server names its provider in X-Feed-Source
(the bundled server sends OpenSky Network, adsb.lol and AISStream, so its
attribution is unchanged) and the military feed's cache state and age in
X-Feed-Cache and X-Feed-Age-Ms. Sources report the provider the server
names and fall back to the feed's name.