[refactor] Simplify Vue node resize to bottom-right corner only (#7063)

## Summary

Temporarily simplifies the resize logic to only work on bottom right
corner and eliminates edge cases where corner resizing caused position
drift issues.

- Remove multi-corner resize handles in favor of bottom-right only
- Delete resizeMath.ts and its tests (no longer needed)
- Simplify useNodeResize to only handle bottom-right resize
- Remove position tracking from resize callback

---------

Co-authored-by: github-actions <github-actions@github.com>

tests-ui/tests/renderer/extensions/vueNodes/interactions/resize/resizeMath.test.ts

@@ -1,94 +0,0 @@
-import { describe, expect, it, vi } from 'vitest'
-
-import {
-  computeResizeOutcome,
-  createResizeSession,
-  toCanvasDelta
-} from '@/renderer/extensions/vueNodes/interactions/resize/resizeMath'
-
-describe('nodeResizeMath', () => {
-  const startSize = { width: 200, height: 120 }
-  const startPosition = { x: 80, y: 160 }
-
-  it('computes resize from bottom-right corner without moving position', () => {
-    const outcome = computeResizeOutcome({
-      startSize,
-      startPosition,
-      delta: { x: 40, y: 20 },
-      handle: { horizontal: 'right', vertical: 'bottom' }
-    })
-
-    expect(outcome.size).toEqual({ width: 240, height: 140 })
-    expect(outcome.position).toEqual(startPosition)
-  })
-
-  it('computes resize from top-left corner adjusting position', () => {
-    const outcome = computeResizeOutcome({
-      startSize,
-      startPosition,
-      delta: { x: -30, y: -20 },
-      handle: { horizontal: 'left', vertical: 'top' }
-    })
-
-    expect(outcome.size).toEqual({ width: 230, height: 140 })
-    expect(outcome.position).toEqual({ x: 50, y: 140 })
-  })
-
-  it('supports reusable resize sessions with snapping', () => {
-    const session = createResizeSession({
-      startSize,
-      startPosition,
-      handle: { horizontal: 'right', vertical: 'bottom' }
-    })
-
-    const snapFn = vi.fn((size: typeof startSize) => ({
-      width: Math.round(size.width / 25) * 25,
-      height: Math.round(size.height / 25) * 25
-    }))
-
-    const applied = session({ x: 13, y: 17 }, snapFn)
-
-    expect(applied.size).toEqual({ width: 225, height: 125 })
-    expect(applied.position).toEqual(startPosition)
-    expect(snapFn).toHaveBeenCalled()
-  })
-
-  it('converts screen delta to canvas delta using scale', () => {
-    const delta = toCanvasDelta({ x: 50, y: 75 }, { x: 150, y: 135 }, 2)
-
-    expect(delta).toEqual({ x: 50, y: 30 })
-  })
-
-  describe('edge cases', () => {
-    it('handles zero scale by using fallback scale of 1', () => {
-      const delta = toCanvasDelta({ x: 50, y: 75 }, { x: 150, y: 135 }, 0)
-
-      expect(delta).toEqual({ x: 100, y: 60 })
-    })
-
-    it('handles negative deltas when resizing from right/bottom', () => {
-      const outcome = computeResizeOutcome({
-        startSize,
-        startPosition,
-        delta: { x: -50, y: -30 },
-        handle: { horizontal: 'right', vertical: 'bottom' }
-      })
-
-      expect(outcome.size).toEqual({ width: 150, height: 90 })
-      expect(outcome.position).toEqual(startPosition)
-    })
-
-    it('handles very large deltas without overflow', () => {
-      const outcome = computeResizeOutcome({
-        startSize,
-        startPosition,
-        delta: { x: 10000, y: 10000 },
-        handle: { horizontal: 'right', vertical: 'bottom' }
-      })
-
-      expect(outcome.size.width).toBe(10200)
-      expect(outcome.size.height).toBe(10120)
-      expect(outcome.position).toEqual(startPosition)
-    })
-  })
-})