In-process WASM test kit package (Python slice)

In-process WASM test kit — Python SDK slice. Consumer ADR: camunda/orchestration-cluster-api-js#459. Engine ABI epic: Magikcraft/nano-bpm#990. Python agnostic core: Magikcraft/nano-bpm#1000. JS reference: camunda/orchestration-cluster-api-js#462. Clock prerequisite: camunda/orchestration-cluster-api-python#258.

Goal

Publish a test-only Python package (or extra) that lets consumers test their SDK-authored applications (processes + workers) against the @nanobpm WASM engine in-process, with no live broker.

It is a thin composition layer over the Python SDK-agnostic core (Magikcraft/nano-bpm#1000); the WASM engine must never land in consumers' production installs.

Deliverables

• create_in_process_client(...) — boots the wasm core, builds a transport shim over its handle(req)->res ABI via a custom httpx transport (e.g. MockTransport/ASGITransport-style) on the SDK client, runs the client with auth disabled, and injects the shared virtual clock (camunda/orchestration-cluster-api-python#258) bound to the engine clock. Returns a real SDK client wired to the in-process engine.
• Assertion surface: bind the agnostic assertThat* DSL to Python SDK types.
• Helpers: deploy, advance clock, run-to-quiescence.
• Runnable conformance fixtures (Magikcraft/nano-bpm#997).
• Example test.

Prerequisites (SDK core)

• A guaranteed transport-injection seam (custom httpx transport) and an auth-disabled mode — audit/expose if missing (mirrors JS camunda/orchestration-cluster-api-js#460 / #461).

Start by auditing the Python SDK's transport-injection seam and auth-disabled mode, then review the agnostic core, JS reference, and shared virtual-clock prerequisite named in the issue. The work is done when the test-only package provides create_in_process_client, assertions, deploy/clock/quiescence helpers, conformance fixtures, and an example without installing the WASM engine in production.