fix: confine Agent and MCP data access

hub/test/unit/feishu-retry.test.ts

@@ -2,7 +2,7 @@ import { afterEach, beforeEach, describe, expect, it, vi, type Mock } from "vite
 import { mkdtemp, rm, writeFile } from "node:fs/promises";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { sendFile, withRetry, type FeishuRuntime } from "../../src/feishu/client.js";
+import { sendFile, sendFileData, withRetry, type FeishuRuntime } from "../../src/feishu/client.js";
 
 describe("withRetry", () => {
   beforeEach(() => {
@@ -127,6 +127,25 @@ describe("sendFile retry", () => {
       await rm(dir, { recursive: true, force: true });
     }
   });
+
+  it("sendFileData preserves an exhausted upload failure as its cause", async () => {
+    vi.useFakeTimers();
+    const cause = new Error("persistent upload failure");
+    const fileCreate = vi.fn(async () => { throw cause; });
+    const rt = mockRuntime({ fileCreate, messageCreate: vi.fn() });
+
+    const result = sendFileData(rt, "chat-1", Buffer.from("pdf bytes"), "student.pdf");
+    const assertion = expect(result).rejects.toMatchObject({
+      name: "FeishuFileDeliveryError",
+      cause,
+    });
+    await Promise.resolve();
+    await vi.advanceTimersByTimeAsync(1000);
+    await vi.advanceTimersByTimeAsync(2000);
+
+    await assertion;
+    expect(fileCreate).toHaveBeenCalledTimes(3);
+  });
 });
 
 async function waitForCalls(mock: Mock, expectedCalls: number): Promise<void> {