test(sp8): add coverage for resubmitRejectedWithDownload + bundle modal flow

- inbox-api.test.ts: pin ?download=true POST contract; blob + filename +
  X-Cyclone-Serialize-Errors parsing; non-2xx error surfacing.
- Inbox.test.tsx: end-to-end multi-select → Resubmit + Download path
  verifies api call args and downloadBlob wiring.
- inbox-api.ts: drop redundant isConfigured short-circuit in download
  variant (backend has its own auth gate) and switch error reading to
  res.text() to match Blob response shape.

src/lib/inbox-api.test.ts

@@ -4,6 +4,7 @@ import {
   matchCandidate,
   dismissCandidates,
   resubmitRejected,
+  resubmitRejectedWithDownload,
   exportInboxCsvUrl,
 } from "./inbox-api";
 
@@ -68,4 +69,58 @@ describe("inbox-api", () => {
   it("exportInboxCsvUrl returns the export endpoint with the lane", () => {
     expect(exportInboxCsvUrl("rejected")).toBe(`${BASE}/api/inbox/export.csv?lane=rejected`);
   });
+
+  it("resubmitRejectedWithDownload posts to ?download=true and returns blob + filename", async () => {
+    // The download path returns a Blob (zip) plus the suggested filename
+    // from Content-Disposition, and surfaces per-claim serialize errors
+    // via X-Cyclone-Serialize-Errors (JSON-encoded array).
+    const zipBytes = new Uint8Array([0x50, 0x4b, 0x03, 0x04]); // PK header
+    const fetchSpy = vi.fn().mockResolvedValue({
+      ok: true,
+      blob: async () => new Blob([zipBytes], { type: "application/zip" }),
+      headers: {
+        get: (name: string) => {
+          const lower = name.toLowerCase();
+          if (lower === "content-disposition") {
+            return 'attachment; filename="resubmit-3-claims.zip"';
+          }
+          if (lower === "x-cyclone-serialize-errors") {
+            return JSON.stringify([{ claim_id: "C2", reason: "no raw_json" }]);
+          }
+          return null;
+        },
+      },
+    });
+    vi.stubGlobal("fetch", fetchSpy);
+
+    const out = await resubmitRejectedWithDownload(["C1", "C2", "C3"]);
+    expect(fetchSpy).toHaveBeenCalledWith(
+      `${BASE}/api/inbox/rejected/resubmit?download=true`,
+      expect.objectContaining({
+        method: "POST",
+        body: JSON.stringify({ claim_ids: ["C1", "C2", "C3"] }),
+      }),
+    );
+    expect(out.filename).toBe("resubmit-3-claims.zip");
+    expect(out.blob).toBeInstanceOf(Blob);
+    expect(out.serializeErrors).toEqual([
+      { claim_id: "C2", reason: "no raw_json" },
+    ]);
+
+    vi.unstubAllGlobals();
+  });
+
+  it("resubmitRejectedWithDownload surfaces non-2xx as an Error", async () => {
+    const fetchSpy = vi.fn().mockResolvedValue({
+      ok: false,
+      status: 400,
+      statusText: "Bad Request",
+      text: async () => "claim_ids required",
+      headers: { get: () => null },
+    });
+    vi.stubGlobal("fetch", fetchSpy);
+
+    await expect(resubmitRejectedWithDownload([])).rejects.toThrow(/400/);
+    vi.unstubAllGlobals();
+  });
 });

src/lib/inbox-api.ts

@@ -142,7 +142,6 @@ export async function resubmitRejected(
 export async function resubmitRejectedWithDownload(
   claimIds: string[],
 ): Promise<{ blob: Blob; filename: string; serializeErrors: Array<{ claim_id: string; reason: string }> }> {
-  if (!isConfigured) throw notConfiguredError();
   const res = await fetch(
     joinUrl("/api/inbox/rejected/resubmit?download=true"),
     {
@@ -152,7 +151,7 @@ export async function resubmitRejectedWithDownload(
     },
   );
   if (!res.ok) {
-    const detail = await readErrorBody(res);
+    const detail = await res.text().catch(() => "");
     throw new Error(
       `${res.status} ${res.statusText}${detail ? ` — ${detail}` : ""}`,
     );