The prod docker build runs `nest build`, which compiles spec files too —
the untyped `vi.fn(async () => undefined)` mock made `queue.add.mock.calls[i]`
a zero-length tuple, so the destructures tripped TS2493/TS2352 and failed
`pnpm build` (tsc --noEmit had skipped the spec). Type the mock args as
unknown[]. No behaviour change; tests still 7/7, `pnpm build` green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>