Defer generated endpoints until API2-owned SDK emitters are ready #61

Why

Kevin decided Python SDK 2.0 ships asyncio over the existing handwritten client surface and a Python 3.12+ floor. Contract-generated endpoints are deferred so API2 owns the SDK emitters instead of maintaining a separate Python-owned contract projection.

Blocked on https://github.com/transloadit/api2/pull/9252 (API2-owned SDK emitters). That work is owned by the existing studio1/~/code/api2 session. Coordinate with that session; do not start a competing emitter or change its claim. There is no promised Python release version for this follow-up.

Recovery snapshot: 8faf570 (the last #57 head before the 2.0 scope reduction). The complete implementation remains in this commit, including:

• scripts/generate_endpoints.py, transloadit/_contract.py, generated blocks in both clients, and contracts/api2-contract.json.gz plus its lock/hash file.
• docs/api-coverage.md, generation packaging/attributes, and the offline CI/tox drift check.
• The 44-operation projection, contract-selected authentication, raw TUS/SSE transport, capability validation, regression/live tests and devdock examples.

This snapshot is reference material for the upstream-owned emitter work, not a release-ready independent generation architecture.

Acceptance after the upstream dependency is ready:

• API2 owns and emits the Python SDK endpoint projection; avoid a new Python-local contract interpreter.
• Import a reviewed producer revision, prove deterministic generation and installed-package/runtime behavior, and restore meaningful wire/cleanup tests.
• Agree the future public endpoint boundary, including the separate-product routes tracked by Deferred storage, device authorization and OAuth API support #60.
• Run repository checks, council review and Ubuntu/Windows/live CI before proposing a future release.

Release-scope context: #57 stacked on #56. All generation artifacts are removed from 2.0.

_{🤖 Released by kvz on framework1/python-sdk since 2026-10-11 · resume: codex resume 01a12c04-6ff8-7a91-9987-654db44d852e}