fix(data): load bundled region packs in the browser; bound region lookups (#743)

The Natural Earth and neighborhood packs were loaded with a JSON-attributed
import(). The Vite dev server answers that request with a JavaScript module,
which the browser rejects, so every analyst region scope failed and fell
through to a geocode lookup that could take 12-28 s.

- src/data/bundledJson.js fetches the pack from a new URL(..., import.meta.url)
  asset in the browser; under Node the caller's attributed import runs.
- resolveRegionRingForQuery caps the geocode + admin-boundary rung at 3 s and
  returns { error: 'region-timeout' }; the lookup keeps running and fills the
  cache. The analyst query reports it as code 'region-timeout'. The Nepal
  locator opts out of the budget.
- Unit tests for the loader, the timeout and the analyst error; the behavior
  harness checks the Gulf of Mexico scope and retries Texas on region-timeout.

Co-authored-by: Bilawal Sidhu <[email protected]>

src/data/neighborhoodPolygons.js

@@ -10,6 +10,7 @@
  * touching this module — see `local_data/neighborhoods/SOURCE.md`.
  */
 
+import { loadBundledJson } from './bundledJson.js';
 import { createRetryableLoader } from './retryableLoad.js';
 
 // bbox = [west, south, east, north]; only load a city file when the point falls in its box.
@@ -17,7 +18,11 @@ const CITY_FILES = [
   {
     id: 'san-francisco',
     bbox: [-122.55, 37.7, -122.35, 37.84],
-    loader: () =>
+    url: new URL(
+      './local_data/neighborhoods/san-francisco.json',
+      import.meta.url,
+    ),
+    importJson: () =>
       import('./local_data/neighborhoods/san-francisco.json', {
         with: { type: 'json' },
       }),
@@ -107,10 +112,7 @@ function cityLoader(city) {
   let loader = _cityLoaders.get(city.id);
   if (!loader) {
     loader = createRetryableLoader(async () => {
-      // One path for both runtimes: Vite bundles the JSON as a module, and the
-      // import attribute is what Node needs to load the same file under node:test.
-      const mod = await city.loader();
-      const fc = mod.default || mod;
+      const fc = await loadBundledJson(city.url, city.importJson);
       return Array.isArray(fc.features) ? fc.features : [];
     });
     _cityLoaders.set(city.id, loader);