fix Vue node opacity conditions (user node opacity, bypass state, muted state) (#6022)

## Summary

Fixed Vue node opacity calculation to properly combine global opacity
setting with muted/bypassed state opacity.

**Root Cause**: When global opacity setting was added as inline style
(481aa8252), it began overriding CSS `opacity-50` classes due to higher
specificity.

**Solution**: Modified `nodeOpacity` computed property to calculate
effective opacity as `globalOpacity * 0.5` for muted/bypassed states,
removing conflicting CSS classes.

## Changes

- **What**: Fixed [CSS specificity
conflict](https://developer.mozilla.org/en-US/docs/Web/CSS/Specificity)
where inline `opacity` style overrode `opacity-50` classes for
muted/bypassed nodes
- **Breaking**: None - restores intended opacity behavior

## Review Focus

Multiplicative opacity calculation ensuring muted/bypassed nodes apply
0.5 opacity on top of global opacity setting rather than being
overridden by it.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6022-fix-Vue-node-opacity-conditions-user-node-opacity-bypass-state-muted-state-2896d73d365081c290f1da37c195c2f5)
by [Unito](https://www.unito.io)

---------

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

browser_tests/tests/vueNodes/nodeStates/bypass.spec.ts

@@ -20,6 +20,9 @@ test.describe('Vue Node Bypass', () => {
 
     const checkpointNode = comfyPage.vueNodes.getNodeByTitle('Load Checkpoint')
     await expect(checkpointNode).toHaveClass(BYPASS_CLASS)
+    await expect(comfyPage.canvas).toHaveScreenshot(
+      'vue-node-bypassed-state.png'
+    )
 
     await comfyPage.page.keyboard.press(BYPASS_HOTKEY)
     await expect(checkpointNode).not.toHaveClass(BYPASS_CLASS)

browser_tests/tests/vueNodes/nodeStates/mute.spec.ts

@@ -4,7 +4,7 @@ import {
 } from '../../../fixtures/ComfyPage'
 
 const MUTE_HOTKEY = 'Control+m'
-const MUTE_CLASS = /opacity-50/
+const MUTE_OPACITY = '0.5'
 
 test.describe('Vue Node Mute', () => {
   test.beforeEach(async ({ comfyPage }) => {
@@ -19,10 +19,11 @@ test.describe('Vue Node Mute', () => {
     await comfyPage.page.keyboard.press(MUTE_HOTKEY)
 
     const checkpointNode = comfyPage.vueNodes.getNodeByTitle('Load Checkpoint')
-    await expect(checkpointNode).toHaveClass(MUTE_CLASS)
+    await expect(checkpointNode).toHaveCSS('opacity', MUTE_OPACITY)
+    await expect(comfyPage.canvas).toHaveScreenshot('vue-node-muted-state.png')
 
     await comfyPage.page.keyboard.press(MUTE_HOTKEY)
-    await expect(checkpointNode).not.toHaveClass(MUTE_CLASS)
+    await expect(checkpointNode).not.toHaveCSS('opacity', MUTE_OPACITY)
   })
 
   test('should allow toggling mute on multiple selected nodes with hotkey', async ({
@@ -35,11 +36,11 @@ test.describe('Vue Node Mute', () => {
     const ksamplerNode = comfyPage.vueNodes.getNodeByTitle('KSampler')
 
     await comfyPage.page.keyboard.press(MUTE_HOTKEY)
-    await expect(checkpointNode).toHaveClass(MUTE_CLASS)
-    await expect(ksamplerNode).toHaveClass(MUTE_CLASS)
+    await expect(checkpointNode).toHaveCSS('opacity', MUTE_OPACITY)
+    await expect(ksamplerNode).toHaveCSS('opacity', MUTE_OPACITY)
 
     await comfyPage.page.keyboard.press(MUTE_HOTKEY)
-    await expect(checkpointNode).not.toHaveClass(MUTE_CLASS)
-    await expect(ksamplerNode).not.toHaveClass(MUTE_CLASS)
+    await expect(checkpointNode).not.toHaveCSS('opacity', MUTE_OPACITY)
+    await expect(ksamplerNode).not.toHaveCSS('opacity', MUTE_OPACITY)
   })
 })