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/naturalEarthRegions.js

@@ -11,11 +11,12 @@
  *
  * PURE data module — no Cesium imports, node-testable. The packs are lazy-
  * loaded on first lookup and cached in module scope (bbox/area computed once
- * at load). In the browser Vite bundles the JSON via dynamic import; under
- * node the same files are read from disk. A failed load is retried on the
- * next lookup rather than cached (see `createRetryableLoader`).
+ * at load) through `loadBundledJson`, which works in the browser and under
+ * node:test. A failed load is retried on the next lookup rather than cached
+ * (see `createRetryableLoader`).
  */
 
+import { loadBundledJson } from './bundledJson.js';
 import { createRetryableLoader } from './retryableLoad.js';
 
 const EARTH_RADIUS_KM = 6371;
@@ -120,20 +121,22 @@ function suffixVariants(norm) {
 /** @type {Array|null} flat entry list for listRegions() */
 let _entries = null;
 
-async function loadPackFile(base) {
-  // Vite bundles these JSON files as modules; the import attribute is what Node
-  // needs to load the same files under node:test (same pattern as
-  // neighborhoodPolygons.js). One path, so no node: import reaches the browser.
-  const mod =
-    base === 'regions'
-      ? await import('./local_data/natural_earth/regions.json', {
-          with: { type: 'json' },
-        })
-      : await import('./local_data/natural_earth/marine.json', {
-          with: { type: 'json' },
-        });
-  return mod.default || mod;
-}
+const PACKS = {
+  regions: {
+    url: new URL('./local_data/natural_earth/regions.json', import.meta.url),
+    importJson: () =>
+      import('./local_data/natural_earth/regions.json', {
+        with: { type: 'json' },
+      }),
+  },
+  marine: {
+    url: new URL('./local_data/natural_earth/marine.json', import.meta.url),
+    importJson: () =>
+      import('./local_data/natural_earth/marine.json', {
+        with: { type: 'json' },
+      }),
+  },
+};
 
 function buildEntries(pack, kind) {
   const out = [];
@@ -175,8 +178,8 @@ function buildEntries(pack, kind) {
  */
 const loadIndex = createRetryableLoader(async () => {
   const [regions, marine] = await Promise.all([
-    loadPackFile('regions'),
-    loadPackFile('marine'),
+    loadBundledJson(PACKS.regions.url, PACKS.regions.importJson),
+    loadBundledJson(PACKS.marine.url, PACKS.marine.importJson),
   ]);
   _entries = [
     ...buildEntries(regions, 'natural'),