- Keyboard Backspace/Delete on the diagram canvas now confirms and
  emits the same entity/relationship delete events the right-click
  menu uses, routing every delete through a single YAML-mutation path.
- Entity and Relationship inspectors now surface a "Danger zone"
  delete button for users who prefer the sidebar over canvas
  shortcuts.
- dbt importer reads `target/catalog.json` (from `dbt docs generate`)
  as a type fallback whenever `manifest.json` lacks `data_type`, so
  projects that only run `dbt docs generate` import real types
  instead of "unknown". Auto-discovered alongside manifest.json;
  missing catalog silently falls through.

Co-authored-by: duckcode2025 <kranthi@duckcode.ai>