Current limitation: The Diagram component only allows pan through mouse interactions (Ctrl+drag). There are no methods to programmatically control the viewport.

Requested feature: Add programmatic viewport control API:

1. PanToAsync(double x, double y) — pan viewport to specific coordinates
   PanByAsync(double deltaX, double deltaY) — pan viewport by offset
   BringIntoViewAsync(IEnumerable<string> shapeIds) — pan/zoom to show specific shapes
   FitToScreenAsync() — auto-zoom to fit all shapes in viewport
2. Pan position binding (optional):
   @bind-PanX / @bind-PanY or PanChanged event
   

Use case:
Programmatic navigation: After adding a new shape, auto-scroll to show it; on search result, navigate to found shape

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Forked from https://feedback.telerik.com/blazor/1708938