Propagate source resolution to review-act and parts CLI children #385

Failure scenario

Run Create with --conditions=@rig-c/source in an isolated sibling-source workspace. The synchronous review-act fetch and parts CLI children omit that condition. They resolve @rig-c/play to play/dist/index.js, so those child paths exercise built Play bytes.

Observed launch points

• src/parts-review.ts:62, src/signoff.ts:57, src/signoff-checkpoint-act.ts:32, src/feedback.ts:552 and src/choice-writers.ts:145 launch create/src/review-act-runtime.ts.
• src/review-read.ts:85 launches the Review package CLI, review/src/entry.ts, for parts review.
• Actual child observations record empty execArgv and resolve Play to play/dist/index.js. The Review job host launched by jobRuntimeCommand already propagates the source condition.

Scope

Carry the supported source condition through these child launchers and preserve default registry resolution. Add actual-child source/default coverage. Keep the source CI observation until the propagation is verified.

This is follow-up to #384. That PR repairs the workspace/build setup and records the current child boundary. It does not change these production launchers. The four-step pilot can continue with built Play after #384.