test(earthquakes): add unit test coverage for earthquake snapshot normalization

- Pin GeoJSON earthquake snapshot normalization contract in src/layers/earthquakes/records.test.mjs
- Cover complete-feed validation, M2.5 magnitude filtering, coordinate and depth bounds
- Verify stable fallback IDs, duplicate ID rejection, and malformed structure handling
- Register records.test.mjs in scripts/format-scope.json and apply Prettier formatting

scripts/format-scope.json

@@ -722,6 +722,7 @@
   "src/voice/session.test.mjs",
   "src/layers/alpr/records.js",
   "src/layers/earthquakes/records.js",
+  "src/layers/earthquakes/records.test.mjs",
   "src/sources/sourceSlot.js",
   "src/data/feedState.js",
   "src/app/localGeojsonServices.js",