When the link inside the subgraph is misaligned with the input.

## Problem

Links inside subgraphs are visually misaligned between Vue nodes and Subgraph IO nodes due to coordinate system inconsistency.

## Root Cause

Vue nodes apply a visual transform offset of `-LiteGraph.NODE_TITLE_HEIGHT` in [LGraphNode.vue:34](https://github.com/Comfy-Org/ComfyUI_frontend/blob/main/src/renderer/extensions/vueNodes/components/LGraphNode.vue#L34), but Subgraph IO nodes use raw canvas coordinates in [SubgraphInput.ts:225-226](https://github.com/Comfy-Org/ComfyUI_frontend/blob/main/src/lib/litegraph/src/subgraph/SubgraphInput.ts#L225-L226).

## Reproduction

1. Enable Vue nodes (`Comfy.VueNodes.Enabled = true`)
2. Create subgraph containing Vue nodes
3. Enter subgraph view
4. Observe misaligned connections between Vue nodes and subgraph IO nodes

## Solution

Update slot position calculation in [useSlotElementTracking.ts](https://github.com/Comfy-Org/ComfyUI_frontend/blob/main/src/renderer/extensions/vueNodes/composables/useSlotElementTracking.ts#L58-L71) to account for Vue node transform offset when calculating connection points.

## Related
- #5706 (subgraph slot connections)
- #5677 (Vue node positioning issues)