Expose LGraphNode.getSlotPosition (#7042)

Before node v2, you could use getInputPos, getOutputPos. In node v2,
that is not possible.

## Summary

Want to get the position of the output / inputs on the graph like before
node v2.

## Changes

- **What**: <!-- Core functionality added/modified --> Added
LGraphNode.getSlotPosition

## Review Focus


## Screenshots (if applicable)

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7042-Expose-LGraphNode-getSlotPosition-2ba6d73d36508195a0fed2d1fe2b64f6)
by [Unito](https://www.unito.io)

src/lib/litegraph/src/LGraphNode.ts

@@ -2,7 +2,8 @@ import { LGraphNodeProperties } from '@/lib/litegraph/src/LGraphNodeProperties'
 import {
   calculateInputSlotPos,
   calculateInputSlotPosFromSlot,
-  calculateOutputSlotPos
+  calculateOutputSlotPos,
+  getSlotPosition
 } from '@/renderer/core/canvas/litegraph/slotCalculations'
 import type { SlotPositionContext } from '@/renderer/core/canvas/litegraph/slotCalculations'
 import { useLayoutMutations } from '@/renderer/core/layout/operations/layoutMutations'
@@ -3354,6 +3355,16 @@ export class LGraphNode
     )
   }
 
+  /**
+   * Get slot position using layout tree if available, fallback to node's position * Unified implementation used by both LitegraphLinkAdapter and useLinkLayoutSync
+   * @param slotIndex The slot index
+   * @param isInput Whether this is an input slot
+   * @returns Position of the slot center in graph coordinates
+   */
+  getSlotPosition(slotIndex: number, isInput: boolean): Point {
+    return getSlotPosition(this, slotIndex, isInput)
+  }
+
   /** @inheritdoc */
   snapToGrid(snapTo: number): boolean {
     return this.pinned ? false : snapPoint(this.pos, snapTo)