dist: Address Copilot review suggestions from PR #1042 (GraalVM Community) (#1059)

- installer: surface a clear error when the GraalVM Community releases
  listing is not a JSON array, instead of silently treating an error
  payload (rate limit, auth failure, etc.) as "no releases" which later
  surfaced as a misleading "version not found" error.
- docs: fix the GraalVM Community advanced-usage example to check the
  installed binary versions (java/native-image --version) rather than
  running a non-existent HelloWorldApp classpath that fails when copied.
- tests: cover the new non-array release listing error path.

Rebuilt dist bundle.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

dist/setup/index.js

@@ -79300,7 +79300,17 @@ class GraalVMCommunityDistribution extends GraalVMDistribution {
             let releasesUrl = GRAALVM_COMMUNITY_RELEASES_URL;
             for (let pageIndex = 0; releasesUrl && pageIndex < util_1.MAX_PAGINATION_PAGES; pageIndex++) {
                 const response = yield this.http.getJson(releasesUrl, headers);
-                const releases = Array.isArray(response.result) ? response.result : [];
+                // A successful GitHub releases listing is always a JSON array (possibly
+                // empty). Anything else indicates an unexpected/error payload (rate
+                // limiting, auth failure, etc.) that must be surfaced instead of being
+                // silently treated as "no releases", which would later look like a
+                // misleading "version not found" error.
+                if (!Array.isArray(response.result)) {
+                    throw new Error(`Unexpected response while listing GraalVM Community releases from ${releasesUrl} ` +
+                        `(HTTP status code: ${response.statusCode}). Expected a JSON array of releases. ` +
+                        `Please check if the service is available at ${GRAALVM_COMMUNITY_DOWNLOAD_URL}.`);
+                }
+                const releases = response.result;
                 if (releases.length === 0) {
                     break;
                 }