feat: name live feed routes and sources for what they serve

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.

scripts/qa-focus-evidence.mjs

@@ -268,11 +268,11 @@ async function installSyntheticFetches(page) {
     }));
     window.fetch = (input, init) => {
       const url = typeof input === 'string' ? input : input?.url || '';
-      if (url.includes('/api/opensky-track')) return json({ path: [] });
-      if (url.includes('/api/adsblol/trace')) return json({ timestamp: Date.now() / 1000, trace: [] });
-      if (url.includes('/api/opensky')) return json({ time: Math.floor(Date.now() / 1000), states: [] });
+      if (url.includes('/api/flights/track')) return json({ path: [] });
+      if (url.includes('/api/military/track')) return json({ timestamp: Date.now() / 1000, trace: [] });
+      if (url.includes('/api/flights')) return json({ time: Math.floor(Date.now() / 1000), states: [] });
       if (url.includes('/api/adsbdb/')) return json({ found: false });
-      if (url.includes('/api/ais-live')) return json({ status: 'open', rows: [] });
+      if (url.includes('/api/vessels')) return json({ status: 'open', rows: [] });
       return realFetch(input, init);
     };
   });