Why: A conversation run has no launch of its own, so a script step looked up an empty copy and refused to run.
Evidence: go test ./internal/runtime/ -run TestRegisteredWorkflowUsesItsOwnScriptCopy passed. The body is taken from the launch passed into the runner.
Impact: Intent-started runs still use the copy made at start.
Refs: feature/agent-harness-p4
Co-authored-by: Cursor <cursoragent@cursor.com>