canonicalize_workflow_config was silently rebuilding any workflow with ui.blueprint or ui.preset == still_graph from the canonical template on every save, preflight, and read — making blueprint-based workflows effectively read-only. Add preserve_user_graph=True flag that skips the rebuild blocks. Only create_workflow still uses preserve_user_graph=False so blueprints are correctly expanded at creation time. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>