test(osm): cover the place-search client and the follow-up handoff

From review:
- The browser client for /api/osm/features gets its own tests (request
  shape, abort, network failure, coded refusals), and a 200 whose body is
  not JSON is now a failure instead of zero places.
- An end-to-end test runs resolve_area, osm_query and an analyst follow-up
  through the real runner and checks the follow-up keeps the area; it fails
  with the wiring reverted.
- The Realtime token test pins Overpass off and compares the full tool
  schemas again instead of names taken from the environment.

scripts/format-scope.json

@@ -1211,6 +1211,7 @@
   "src/tooling/nominatimOutlineRoute.test.mjs",
   "src/data/areaGeometry.test.mjs",
   "src/data/areaResolver.test.mjs",
+  "src/sources/osmFeatures.test.mjs",
   "src/layers/osmPlaces/index.test.mjs",
   "src/tooling/boundedCache.test.mjs",
   "src/tooling/osmFeaturesRoute.test.mjs",