fix(producer): transport safe extraction failure metadata (#3592)

* fix(producer): transport safe extraction failure metadata

* refactor(producer): generalize public error metadata

* test(producer): use vendor-neutral media hosts

packages/engine/src/utils/urlDownloader.test.ts

@@ -447,6 +447,7 @@ describe("downloadToTemp atomic publication and bounded retry", () => {
     ).rejects.toMatchObject({
       kind: "length_mismatch",
       retryable: true,
+      telemetry: expect.objectContaining({ attempt: 2 }),
     } satisfies Partial<UrlDownloadError>);
     expect(fetchMock).toHaveBeenCalledTimes(2);
     expect(readdirSync(dir).filter((name) => name.startsWith("download_"))).toEqual([]);
@@ -802,6 +803,7 @@ describe("downloadToTemp atomic publication and bounded retry", () => {
     ).rejects.toMatchObject({
       kind: "invalid_payload",
       retryable: false,
+      telemetry: expect.objectContaining({ attempt: 1 }),
     } satisfies Partial<UrlDownloadError>);
     expect(fetchMock).toHaveBeenCalledTimes(1);
     expect(temporaryDownloadEntries(dir)).toEqual([]);

packages/engine/src/utils/urlDownloader.ts

@@ -1113,7 +1113,22 @@ async function downloadWithRetry(
       return await runDownloadAttempt(url, localPath, timeoutMs, attempt + 1, options, signal);
     } catch (error) {
       const classified = classifyDownloadFailure(error);
-      if (!classified.locallyRetryable || attempt >= maxTransientRetries) throw classified;
+      if (!classified.locallyRetryable || attempt >= maxTransientRetries) {
+        const identity = safeDownloadUrlIdentity(url);
+        throw new UrlDownloadError(
+          classified.kind,
+          classified.retryable,
+          classified.message,
+          classified.status,
+          {
+            ...classified.telemetry,
+            urlFingerprint: identity.urlFingerprint,
+            initialHost: identity.host,
+            attempt: attempt + 1,
+          },
+          classified.locallyRetryable,
+        );
+      }
       if (classified.retryable) onTransientRetry?.(classified);
       const identity = safeDownloadUrlIdentity(url);
       emitDownloadTelemetry(options, {