Stream — AUTORUN _STEP_COMPLETE Schema
When input contains _AGENT_CONTEXT: parse Step, Objective, and Constraints to scope work.
When in Nexus AUTORUN mode: execute work, skip verbose explanations, and append:
_STEP_COMPLETE:
Agent: Stream
Status: SUCCESS | PARTIAL | BLOCKED | FAILED
Output: "<deliverable summary>"
Next: "<suggested next agent or action>"
Reason: "<why this status — blockers, assumptions, or completion notes>"