Branch **`feat/native-wire-udf`** · rewrite of the lakeshore Python SDK from
first principles. msgpack (the library) and the `Storage` broker survive;
everything above them is new. No zaku code — its *lessons* are encoded as
conformance tests.

## Progress

| Phase | What | State |
|---|---|---|
| 0 | `wire.py` — ExtType codec, versioned `Envelope`, `Frame` + reader | ✅ |
| 1 | `context.py` — `dls.run` seam, string-key returns, key contract, lazy root | ✅ |
| 2 | `dispatch.py` minimal plane ✅ · `functions.py` native `@udf` ✅ · Queue/SyncQueue ✅ · httpx transport ✅ · worker loop ✅ · legacy deletion ✅ | ✅ |
| 3 | Real streaming (Node CP Redis-Streams journal) · e2e + examples rework | ⬜ |
| 4 | dreamlake collections merge + dispatch-plane split | ⬜ |

**Tests: 113 passed** (SDK unit; legacy tests deleted with the legacy
surface) · control plane baseline 599 ✅ · dreamlake-server 108/109
(1 pre-existing failure, documented).

## The locked design, in one breath

Zero new value types — data UDFs return **string keys**; file bytes never
ride the wire (worker↔storage side channel via `dls.run.read/write`); the
function's own shape picks execution (sync/async/generator/async-gen) and
transfer timing (return = upload-then-return, async-gen = stream partial
manifests); **no Future** — the durable handle is the invocation id;
`Queue` async-first with `SyncQueue` sibling; local tier imports nothing
distributed; every dispatch transition is one guarded atomic UPDATE
(fencing, idempotent submit, counts==contents by construction).

## Documents

- [Native API + type system design](/python-sdk/rewrite/design.md) — the synthesized
  design, dual-ergonomics audit, and concept-by-concept zaku comparison.
  *(Historical note: its `Ref` recommendation was superseded by the
  zero-types / string-keys decision recorded here and in the API pages.)*
- [Usage surface & test plan](/python-sdk/rewrite/test-plan.md) — 113 CP
  routes × 7 consumers × 3 encodings, and the automatable test strategy.

## New modules (API)

- [`wire`] — codec, envelope, frames
- [`context`] — the `dls.run` I/O seam
- [`dispatch`] / [`http_dispatch`] — the dispatch planes
  ([API page](/python-sdk/dispatch.md))
- [`functions`] — the native `@udf` ([API page](/python-sdk/udf.md))
- [`queues`] — Queue / SyncQueue / Topic ([API page](/python-sdk/queue.md))
- [`worker`] — the claim-and-execute loop

The user-facing [Python SDK section](/python-sdk.md) now documents this
native surface.