Fixes that surfaced once users started actually building diagrams on
top of v0.5.0:

- Entity moves persist on wildcard-sourced diagrams
- Diagram relationships survive tab switches and browser reloads
- dbt import + every CLI shell-out works from a dev clone again
  (dm → datalex launcher path)
- Entity delete cascades through relationships, indexes, metrics, and
  governance entries; success toast lists the impact
- Model Graph panel auto-refreshes after save / delete / rename