Improve jitter on snapping plugins

[jesusmpc]

Problem

When dragging nodes, especially with many visible elements and when both plugins are active simultaneously, noticeable jitter occurs during:

• Edge snapping
• Distance snapping

In some scenarios, nodes “jump” between snap positions, suggesting conflicting snap resolutions between plugins.

This degrades UX and makes snapping feel unstable.

• Edge and Distance plugins both modify node position during the same dragmove.
• No arbitration or priority system exists.
• Results in snap “tug-of-war”.

Acceptance Criteria

• No visible jitter under heavy layout density.
• No snap fighting between plugins.
• Stable snap lock until exit tolerance exceeded.
• Deterministic snap resolution per axis.
• Performance remains stable at scale.