feat: add ship tools

Add vessels_in_area, find_vessel and get_vessel_track over the live
vessel source, and a ships section in situation_brief. Without an AIS
key the source's own message reaches clients as an unavailable feed.

scripts/format-scope.json

@@ -876,5 +876,6 @@
   "src/tools/queries/places.test.mjs",
   "src/layers/transit/source.test.mjs",
   "src/tools/queries/mobility.test.mjs",
-  "src/tools/queries/environment.test.mjs"
+  "src/tools/queries/environment.test.mjs",
+  "src/tools/queries/maritime.test.mjs"
 ]