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/analystEngine.js

@@ -18,7 +18,7 @@
  *
  * Providers (injected — keeps the engine pure and node-testable):
  *   getRecords(layerKey) → Array<record>            (layer accessor snapshot)
- *   resolveRegionRing(name) → Promise<{ring, name}|null>  (NE pack / admin boundary)
+ *   resolveRegionRing(name) → Promise<{ring, name}|{error:'region-timeout'}|null>
  *   getViewContext() → {lat, lon, viewRadiusKm, bounds?}  (camera-derived)
  *
  * @module data/analystEngine
@@ -234,6 +234,14 @@ export function createAnalystEngine(providers) {
     const scope = spec.scope || { kind: 'view' };
     if (scope.kind === 'region' && scope.name) {
       const region = await providers.resolveRegionRing(scope.name);
+      if (region?.error === 'region-timeout') {
+        return {
+          ok: false,
+          code: 'region-timeout',
+          error: `Looking up the boundary for "${scope.name}" is taking too long — ask again in a moment.`,
+          coverage: { layersQueried, scope: `region:${scope.name}:timeout` },
+        };
+      }
       if (!region?.ring) {
         return {
           ok: false,