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/bundledJson.js

@@ -0,0 +1,29 @@
+/**
+ * @file Load a JSON file shipped beside the source modules.
+ *
+ * The browser fetches the file from `url` — a `new URL('./….json',
+ * import.meta.url)` written in the calling module, which Vite serves as-is in
+ * dev and emits as an asset in the production build. Under Node (node:test)
+ * that URL is a `file:` URL, which `fetch` cannot read, so the caller's
+ * JSON-attributed import runs instead.
+ *
+ * The attributed import cannot serve the browser: the Vite dev server answers
+ * it with a JavaScript module, which the browser rejects for a JSON import.
+ *
+ * @module data/bundledJson
+ */
+
+/**
+ * @param {URL} url - Resolved against the calling module's `import.meta.url`.
+ * @param {() => Promise<{default: any}>} importJson - The caller's literal
+ *   `import('./….json', { with: { type: 'json' } })`, used only under Node.
+ * @returns {Promise<any>} The parsed JSON.
+ */
+export async function loadBundledJson(url, importJson) {
+  if (url.protocol === 'file:') return (await importJson()).default;
+  const response = await fetch(url);
+  if (!response.ok) {
+    throw new Error(`HTTP ${response.status} for ${url.pathname}`);
+  }
+  return response.json();
+}