Add CBOR queue transport helpers for Workflow SDK spec v3

[VaguelySerious]

Summary

Workflow SDK recently moved the `@workflow/world-vercel` queue transport from JSON to CBOR (vercel/workflow#1627). The move is gated behind `SPEC_VERSION_SUPPORTS_CBOR_QUEUE_TRANSPORT` (spec version 3) so worlds that don't declare support stay on JSON.

This PR adds the CBOR transport building blocks to each world in this repo so they can eventually opt in. It intentionally does not flip any of the queues over — the full migration is larger than this and deserves careful review on a per-world basis.

What's in the PR

• `packages/turso/src/cbor-transport.ts` — `CborTransport` + `DualTransport` (CBOR-first, JSON fallback) mirroring `@workflow/world-vercel`'s implementation.
• `packages/mongodb/src/cbor-transport.ts` — same pair. Adds `cbor-x` as a dependency (mongodb didn't have it yet).
• `packages/redis/src/cbor-transport.ts` — same pair plus `encodeForBullMq`/`decodeFromBullMq` helpers. BullMQ stores `job.data` as a JSON value, so the CBOR payload is wrapped as a base64 string on the way in and unwrapped in the processor before the HTTP POST. Adds `@vercel/queue` as a dependency to match the other packages.
• Three changesets (`patch`) so these show up in the next release train.

Background from upstream

• Resilient start ([core] [world] Lazy run creation on start vercel/workflow#1537) added a `runInput` payload that rides on the first queue delivery. The input field is a `Uint8Array`.
• CBOR queue transport ([core] [world] Gate CBOR queue transport on specVersion vercel/workflow#1627) flipped `@workflow/world-vercel` over because JSON drops `Uint8Array` on the floor. It bumped `SPEC_VERSION_CURRENT` to 3, so any world whose `specVersion` is 3+ needs a transport that preserves `Uint8Array`.
• Spec version gate ([core] [world] Fix community world E2E tests broken by specVersion bump vercel/workflow#1658) keeps worlds on spec v2 by default, which is why the worlds in this repo are still compatible today — the SDK does not send them `runInput` over the queue.

In short: nothing is breaking today because these worlds haven't declared `specVersion`. But they also can't opt in to resilient start (or any future CBOR-only feature) until a transport like this is wired up.

Why not wire it in here?

These packages currently pin `@workflow/world: 4.1.0-beta.2`, which is a pre-v5 shape (flat `writeToStream`/`readFromStream` on the `World`). `@workflow/world@5.x` restructures streams into a nested `streams.{ write, close, get, list, getChunks, getInfo }` interface and requires `runId` on reads. Migrating to v5 is a prerequisite for spec v3 and I didn't want to bundle that migration into this PR — it's significant enough to deserve its own review pass (and will break the current consumer story on 4.1.x betas).

Suggested follow-up checklist

For each world (turso, mongodb, redis):

1. Bump `@workflow/world` to `^5.0.0-beta.1` (the first 5.x beta to export `SPEC_VERSION_SUPPORTS_CBOR_QUEUE_TRANSPORT`) and corresponding `@workflow/errors` / `@workflow/world-testing` versions.
2. Migrate the world to the new `streams.*` shape (`writeToStream(name, runId, chunk)` → `streams.write(runId, name, chunk)`, etc.). This is the bulk of the work.
3. Swap `new JsonTransport()` for `new CborTransport()` on the send path and `new DualTransport()` on the receive path in `queue.ts`. For Redis, wrap `job.data` with `encodeForBullMq` / `decodeFromBullMq` at the queue/worker boundary.
4. For Turso, change the `queue_messages.payload` column from `TEXT` to `BLOB` (or base64-wrap the CBOR bytes) — CBOR is binary and will not round-trip as UTF-8 text.
5. Honor `opts?.specVersion` in `queue()`: fall back to `JsonTransport` when `specVersion < 3` so existing runs continue to use the format they were created with.
6. Declare `specVersion: SPEC_VERSION_SUPPORTS_CBOR_QUEUE_TRANSPORT` on the exported world so the SDK creates new runs at v3.
7. Extend the e2e tests to exercise `runInput` (start a workflow with a binary input and assert it round-trips).

Happy to split out per-world follow-up PRs if that's easier to review.

Test plan

• `pnpm typecheck` passes for `@workflow-worlds/{turso,mongodb,redis}`.
• Once wired in: existing e2e suite passes + new test exercising `Uint8Array` `runInput`.

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