Is your feature request related to a problem? Please describe

Currently, the Graph.defaultLoopStyle property directly references the EdgeStyle.Loop implementation. This hardcoded link limits flexibility and makes tree shaking impossible for users who do not rely on loop edges in their application.

Describe the solution you'd like

We’d like to make Graph.defaultLoopStyle accept a string name referring to a registered edge style, not the direct function reference. For example: "loopEdgeStyle" instead of EdgeStyle.Loop.

• It should support both a string or a function (like other edge-related props).
• The default value can stay "loopEdgeStyle", to ensure backward compatibility.
• This change would reduce unnecessary bundle size for apps that don’t use loops.

Notes

• this will introduce a breaking change for people relying on the default loop implementation
• now, they will have to be sure that the loop edge style is registered when using BaseGraph
• when using Graph, there will be no change as the loop edge style is registered in that case

Describe alternatives you've considered

Keeping the function reference in place hardcodes the dependency and prevents tree shaking.

This is not the same as the default edge, vertex, and label shapes defined in CellRenderer. Those are critical default implementations: without defaultVertexShape, defaultEdgeShape, or defaultTextShape, cells wouldn’t render at all.

These are the only concrete shape implementations that should be part of the codebase. Everything else - including loop styles - should ideally be configurable through registration.

• defaultVertexShape = RectangleShape
• defaultEdgeShape = ConnectorShape
• defaultTextShape = TextShape

But unlike these core shapes, the loop edge style is not essential and shouldn’t be hardcoded.

Additional context

• Allow string values for Graph.defaultLoopStyle. This would make the loop style consistent with other configurable elements via registration.

Graph.defaultLoopStyle = "loopEdgeStyle";
// OR
Graph.defaultLoopStyle = EdgeStyle.Loop;

• We should also:
  • Add a Storybook story showing different loop configurations:
    • default loop from Graph
    • custom style with loopStyle
    • custom style with noLoop
    • custom style with orthogonalLoop
  • ⚠️ Fix mismatch in the CellStateStyle.orthogonalLoop JSDoc: currently mentions OrthConnector, but it's not used. Either the code or the JSDoc should be updated to reflect the actual implementation.