perf: add gpu hint and transform settle to prevent rasterizing while zooming (scale transform) (#7417)

## Summary

Ensures the nodes get their own compositing layers during scale
transform (tracked via mouse wheel events), which prevents rasterization
during transform. Adds forced reflow at end of transform to ensure
layers are always at correct resolution (fixes blurriness and some
readability issues).

Videos show testing this branch first then testing main - doing layer
visualization, paint (include paint operations calculations and actual
raster) visualizations, and cpu usage monitoring.


https://github.com/user-attachments/assets/c5fab219-0b32-4822-9238-c4572f0d6a44



https://github.com/user-attachments/assets/7e172e8d-cc5b-4dcd-aa07-1dfc3eb65bac

tests-ui/tests/composables/graph/useTransformSettling.test.ts

@@ -0,0 +1,171 @@
+import { mount } from '@vue/test-utils'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { nextTick, ref } from 'vue'
+
+import { useTransformSettling } from '@/renderer/core/layout/transform/useTransformSettling'
+
+describe('useTransformSettling', () => {
+  let element: HTMLDivElement
+
+  beforeEach(() => {
+    vi.useFakeTimers()
+    element = document.createElement('div')
+    document.body.appendChild(element)
+  })
+
+  afterEach(() => {
+    vi.useRealTimers()
+    document.body.removeChild(element)
+  })
+
+  it('should track wheel events and settle after delay', async () => {
+    const { isTransforming } = useTransformSettling(element, {
+      settleDelay: 200
+    })
+
+    // Initially not transforming
+    expect(isTransforming.value).toBe(false)
+
+    // Dispatch wheel event
+    element.dispatchEvent(new WheelEvent('wheel', { bubbles: true }))
+    await nextTick()
+
+    // Should be transforming
+    expect(isTransforming.value).toBe(true)
+
+    // Advance time but not past settle delay
+    vi.advanceTimersByTime(100)
+    expect(isTransforming.value).toBe(true)
+
+    // Advance past settle delay
+    vi.advanceTimersByTime(150)
+    expect(isTransforming.value).toBe(false)
+  })
+
+  it('should reset settle timer on subsequent wheel events', async () => {
+    const { isTransforming } = useTransformSettling(element, {
+      settleDelay: 300
+    })
+
+    // First wheel event
+    element.dispatchEvent(new WheelEvent('wheel', { bubbles: true }))
+    await nextTick()
+    expect(isTransforming.value).toBe(true)
+
+    // Advance time partially
+    vi.advanceTimersByTime(200)
+    expect(isTransforming.value).toBe(true)
+
+    // Another wheel event should reset the timer
+    element.dispatchEvent(new WheelEvent('wheel', { bubbles: true }))
+    await nextTick()
+
+    // Advance 200ms more - should still be transforming
+    vi.advanceTimersByTime(200)
+    expect(isTransforming.value).toBe(true)
+
+    // Need another 100ms to settle (300ms total from last event)
+    vi.advanceTimersByTime(100)
+    expect(isTransforming.value).toBe(false)
+  })
+
+  it('should not track pan events', async () => {
+    const { isTransforming } = useTransformSettling(element)
+
+    // Pointer events should not trigger transform
+    element.dispatchEvent(new PointerEvent('pointerdown', { bubbles: true }))
+    element.dispatchEvent(new PointerEvent('pointermove', { bubbles: true }))
+    await nextTick()
+
+    expect(isTransforming.value).toBe(false)
+  })
+
+  it('should work with ref target', async () => {
+    const targetRef = ref<HTMLElement | null>(null)
+    const { isTransforming } = useTransformSettling(targetRef, {
+      settleDelay: 200
+    })
+
+    // No target yet
+    expect(isTransforming.value).toBe(false)
+
+    // Set target
+    targetRef.value = element
+    await nextTick()
+
+    // Now events should work
+    element.dispatchEvent(new WheelEvent('wheel', { bubbles: true }))
+    await nextTick()
+    expect(isTransforming.value).toBe(true)
+
+    vi.advanceTimersByTime(200)
+    expect(isTransforming.value).toBe(false)
+  })
+
+  it('should use capture phase for events', async () => {
+    const captureHandler = vi.fn()
+    const bubbleHandler = vi.fn()
+
+    // Add handlers to verify capture phase
+    element.addEventListener('wheel', captureHandler, true)
+    element.addEventListener('wheel', bubbleHandler, false)
+
+    const { isTransforming } = useTransformSettling(element)
+
+    // Create child element
+    const child = document.createElement('div')
+    element.appendChild(child)
+
+    // Dispatch event on child
+    child.dispatchEvent(new WheelEvent('wheel', { bubbles: true }))
+    await nextTick()
+
+    // Capture handler should be called before bubble handler
+    expect(captureHandler).toHaveBeenCalled()
+    expect(isTransforming.value).toBe(true)
+
+    element.removeEventListener('wheel', captureHandler, true)
+    element.removeEventListener('wheel', bubbleHandler, false)
+  })
+
+  it('should clean up event listeners when component unmounts', async () => {
+    const removeEventListenerSpy = vi.spyOn(element, 'removeEventListener')
+
+    // Create a test component
+    const TestComponent = {
+      setup() {
+        const { isTransforming } = useTransformSettling(element)
+        return { isTransforming }
+      },
+      template: '<div>{{ isTransforming }}</div>'
+    }
+
+    const wrapper = mount(TestComponent)
+    await nextTick()
+
+    // Unmount component
+    wrapper.unmount()
+
+    // Should have removed wheel event listener
+    expect(removeEventListenerSpy).toHaveBeenCalledWith(
+      'wheel',
+      expect.any(Function),
+      expect.objectContaining({ capture: true })
+    )
+  })
+
+  it('should use passive listeners when specified', async () => {
+    const addEventListenerSpy = vi.spyOn(element, 'addEventListener')
+
+    useTransformSettling(element, {
+      passive: true
+    })
+
+    // Check that passive option was used for wheel event
+    expect(addEventListenerSpy).toHaveBeenCalledWith(
+      'wheel',
+      expect.any(Function),
+      expect.objectContaining({ passive: true, capture: true })
+    )
+  })
+})