refactor/runtime-descriptor-boundary
main
Collapse bundle/cas/extract/util stubs into types.ts; move createWorkflow and Result helpers to src root. Co-authored-by: Cursor <cursoragent@cursor.com>
Keep @uncaged/workflow-runtime focused on bundle runtime capabilities by relocating descriptor validation implementation to @uncaged/workflow. Co-authored-by: Cursor <cursoragent@cursor.com>