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/browserModuleBoundary.test.mjs

@@ -22,7 +22,7 @@ test('no browser-built module imports a Node core module', () => {
   // import survives the build and turns into a runtime failure the moment the
   // guard around it is wrong. src/data/naturalEarthRegions.js and
   // src/data/neighborhoodPolygons.js both carried one to read their bundled
-  // JSON packs under node:test; an import attribute serves both runtimes.
+  // JSON packs under node:test; src/data/bundledJson.js now serves both runtimes.
   const offenders = [];
   for (const file of browserModules()) {
     const source = readFileSync(file, 'utf8');