fix: Improve legacy widget compatibility in vueNodes mode (#7766)

## Summary
- Fix widget callback signature to pass node as 3rd parameter for
extensions like Impact Pack
- Add triggerDraw call to update all legacy widgets when any widget
value changes
- Support computeLayoutSize for dynamic widget height calculation
- Set node.canvasHeight for extensions that rely on this property
- Use step/10 for number input buttons to match litegraph behavior

Fixes display and interaction issues with Impact Pack's Mask Rect Area
nodes.

fix https://github.com/Comfy-Org/ComfyUI_frontend/issues/7615 and
https://github.com/Comfy-Org/ComfyUI_frontend/issues/7616

it also requires Impact pack PR
https://github.com/ltdrdata/ComfyUI-Impact-Pack/pull/1167

## Screenshots
Before


https://github.com/user-attachments/assets/eb890f7c-c1a0-4c7b-a8d7-dde304de83e4


After


https://github.com/user-attachments/assets/dad65b52-d71e-4c19-92c0-367b7dcafed0

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7766-fix-Improve-legacy-widget-compatibility-in-vueNodes-mode-2d56d73d365081b18d83f4a41ff0f377)
by [Unito](https://www.unito.io)

src/renderer/extensions/vueNodes/widgets/composables/useNumberStepCalculation.ts

@@ -2,6 +2,7 @@ import { computed, toValue } from 'vue'
 import type { MaybeRefOrGetter } from 'vue'
 
 interface NumberWidgetOptions {
+  step?: number
   step2?: number
   precision?: number
 }
@@ -17,10 +18,17 @@ export function useNumberStepCalculation(
 ) {
   return computed(() => {
     const precision = toValue(precisionArg)
-    // Use step2 (correct input spec value) instead of step (legacy 10x value)
+    // Use step2 (correct input spec value) if available
     if (options?.step2 !== undefined) {
       return Number(options.step2)
     }
+    // Use step / 10 for custom large step values (> 10) to match litegraph behavior
+    // This is important for extensions like Impact Pack that use custom step values (e.g., 640)
+    // We skip default step values (1, 10) to avoid affecting normal widgets
+    const step = options?.step
+    if (step !== undefined && step > 10) {
+      return Number(step) / 10
+    }
 
     if (precision === undefined) {
       return returnUndefinedForDefault ? undefined : 0
@@ -29,7 +37,9 @@ export function useNumberStepCalculation(
     if (precision === 0) return 1
 
     // For precision > 0, step = 1 / (10^precision)
-    const step = 1 / Math.pow(10, precision)
-    return returnUndefinedForDefault ? step : Number(step.toFixed(precision))
+    const calculatedStep = 1 / Math.pow(10, precision)
+    return returnUndefinedForDefault
+      ? calculatedStep
+      : Number(calculatedStep.toFixed(precision))
   })
 }