fix(memory): discard stdout for qmd update/embed to prevent output cap failure (openclaw#28900) thanks @Glucksberg

Verified:
- pnpm install --frozen-lockfile
- pnpm build
- pnpm check
- pnpm test:macmini

Co-authored-by: Glucksberg <80581902+Glucksberg@users.noreply.github.com>
Co-authored-by: Tak Hoffman <781889+Takhoffman@users.noreply.github.com>

src/memory/qmd-manager.test.ts

@@ -1761,6 +1761,25 @@ describe("QmdMemoryManager", () => {
     }
   });
 
+  it("succeeds on qmd update even when stdout exceeds the output cap", async () => {
+    // Regression test for #24966: large indexes produce >200K chars of stdout
+    // during `qmd update`, which used to fail with "produced too much output".
+    const largeOutput = "x".repeat(300_000);
+    spawnMock.mockImplementation((_cmd: string, args: string[]) => {
+      if (args[0] === "update") {
+        const child = createMockChild({ autoClose: false });
+        emitAndClose(child, "stdout", largeOutput);
+        return child;
+      }
+      return createMockChild();
+    });
+
+    const { manager } = await createManager({ mode: "status" });
+    // sync triggers runQmdUpdateOnce -> runQmd(["update"], { discardOutput: true })
+    await expect(manager.sync({ reason: "manual" })).resolves.toBeUndefined();
+    await manager.close();
+  });
+
   it("scopes by channel for agent-prefixed session keys", async () => {
     cfg = {
       ...cfg,