refactor: replace runtime isElectron() with build-time isDesktop constant (#8710)

## Summary

Replace all runtime `isElectron()` function calls with the build-time
`isDesktop` constant from `@/platform/distribution/types`, enabling
dead-code elimination in non-desktop builds.

## Changes

- **What**: Migrate 30 files from runtime `isElectron()` detection
(checking `window.electronAPI`) to the compile-time `isDesktop` constant
(driven by `__DISTRIBUTION__` Vite define). Remove `isElectron` from
`envUtil.ts`. Update `isNativeWindow()` to use `isDesktop`. Guard
`electronAPI()` calls behind `isDesktop` checks in stores. Update 7 test
files to use `vi.hoisted` + getter mock pattern for per-test `isDesktop`
toggling. Add `DISTRIBUTION=desktop` to `dev:electron` script.

## Review Focus

- The `electronDownloadStore.ts` now guards the top-level
`electronAPI()` call behind `isDesktop` to prevent crashes on
non-desktop builds.
- Test mocking pattern uses `vi.hoisted` with a getter to allow per-test
toggling of the `isDesktop` value.
- Pre-existing issues not addressed: `as ElectronAPI` cast in
`envUtil.ts`, `:class="[]"` in `BaseViewTemplate.vue`,
`@ts-expect-error` in `ModelLibrarySidebarTab.vue`.
- This subsumes PR #8627 and renders PR #6122 and PR #7374 obsolete.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8710-refactor-replace-runtime-isElectron-with-build-time-isDesktop-constant-3006d73d365081c08037f0e61c2f6c77)
by [Unito](https://www.unito.io)

src/platform/distribution/types.ts

@@ -1,5 +1,3 @@
-import { isElectron } from '@/utils/envUtil'
-
 /**
  * Distribution types and compile-time constants for managing
  * multi-distribution builds (Desktop, Localhost, Cloud)
@@ -15,10 +13,8 @@ declare global {
 /** Current distribution - replaced at compile time */
 const DISTRIBUTION: Distribution = __DISTRIBUTION__
 
-/** Distribution type checks */
-export const isDesktop = DISTRIBUTION === 'desktop' || isElectron() // TODO: replace with build var
+export const isDesktop = DISTRIBUTION === 'desktop'
 export const isCloud = DISTRIBUTION === 'cloud'
-// export const isLocalhost = DISTRIBUTION === 'localhost' || (!isDesktop && !isCloud)
 
 /**
  * Whether this is a nightly build (from main branch).

src/platform/settings/composables/useSettingUI.ts

@@ -6,11 +6,11 @@ import { useCurrentUser } from '@/composables/auth/useCurrentUser'
 import { useBillingContext } from '@/composables/billing/useBillingContext'
 import { useFeatureFlags } from '@/composables/useFeatureFlags'
 import { useVueFeatureFlags } from '@/composables/useVueFeatureFlags'
-import { isCloud } from '@/platform/distribution/types'
+import { isCloud, isDesktop } from '@/platform/distribution/types'
 import type { SettingTreeNode } from '@/platform/settings/settingStore'
 import { useSettingStore } from '@/platform/settings/settingStore'
 import type { SettingParams } from '@/platform/settings/types'
-import { isElectron } from '@/utils/envUtil'
+
 import { normalizeI18nKey } from '@/utils/formatUtil'
 import { buildTree } from '@/utils/treeUtil'
 
@@ -226,7 +226,7 @@ export function useSettingUI(
       ...(shouldShowWorkspacePanel.value ? [workspacePanel] : []),
       keybindingPanel,
       extensionPanel,
-      ...(isElectron() ? [serverConfigPanel] : []),
+      ...(isDesktop ? [serverConfigPanel] : []),
       ...(shouldShowPlanCreditsPanel.value && subscriptionPanel
         ? [subscriptionPanel]
         : []),
@@ -283,7 +283,7 @@ export function useSettingUI(
         translateCategory(keybindingPanel.node),
         translateCategory(extensionPanel.node),
         translateCategory(aboutPanel.node),
-        ...(isElectron() ? [translateCategory(serverConfigPanel.node)] : [])
+        ...(isDesktop ? [translateCategory(serverConfigPanel.node)] : [])
       ]
     }),
     // Custom node settings (only shown if custom nodes have registered settings)
@@ -332,7 +332,7 @@ export function useSettingUI(
         keybindingPanel.node,
         extensionPanel.node,
         aboutPanel.node,
-        ...(isElectron() ? [serverConfigPanel.node] : [])
+        ...(isDesktop ? [serverConfigPanel.node] : [])
       ].map(translateCategory)
     }
   ])

src/platform/updates/common/releaseStore.test.ts

@@ -9,7 +9,6 @@ import { useSettingStore } from '@/platform/settings/settingStore'
 import { useReleaseStore } from '@/platform/updates/common/releaseStore'
 import { useReleaseService } from '@/platform/updates/common/releaseService'
 import { useSystemStatsStore } from '@/stores/systemStatsStore'
-import { isElectron } from '@/utils/envUtil'
 import { createTestingPinia } from '@pinia/testing'
 import type { SystemStats } from '@/types'
 
@@ -19,11 +18,14 @@ vi.mock('semver', () => ({
   valid: vi.fn(() => '1.0.0')
 }))
 
-vi.mock('@/utils/envUtil', () => ({
-  isElectron: vi.fn(() => true)
-}))
+const mockData = vi.hoisted(() => ({ isDesktop: true }))
 
-vi.mock('@/platform/distribution/types', () => ({ isCloud: false }))
+vi.mock('@/platform/distribution/types', () => ({
+  get isDesktop() {
+    return mockData.isDesktop
+  },
+  isCloud: false
+}))
 
 vi.mock('@/platform/updates/common/releaseService', () => {
   const getReleases = vi.fn()
@@ -675,10 +677,10 @@ describe('useReleaseStore', () => {
     })
   })
 
-  describe('isElectron environment checks', () => {
-    describe('when running in Electron (desktop)', () => {
+  describe('isDesktop environment checks', () => {
+    describe('when running on desktop', () => {
       beforeEach(() => {
-        vi.mocked(isElectron).mockReturnValue(true)
+        mockData.isDesktop = true
       })
 
       it('should show toast when conditions are met', () => {
@@ -709,9 +711,9 @@ describe('useReleaseStore', () => {
       })
     })
 
-    describe('when NOT running in Electron (web)', () => {
+    describe('when NOT running on desktop (web)', () => {
       beforeEach(() => {
-        vi.mocked(isElectron).mockReturnValue(false)
+        mockData.isDesktop = false
       })
 
       it('should NOT show toast even when all other conditions are met', () => {

src/platform/updates/common/releaseStore.ts

@@ -3,10 +3,9 @@ import { defineStore } from 'pinia'
 import { compare, valid } from 'semver'
 import { computed, ref } from 'vue'
 
-import { isCloud } from '@/platform/distribution/types'
+import { isCloud, isDesktop } from '@/platform/distribution/types'
 import { useSettingStore } from '@/platform/settings/settingStore'
 import { useSystemStatsStore } from '@/stores/systemStatsStore'
-import { isElectron } from '@/utils/envUtil'
 import { stringToLocale } from '@/utils/formatUtil'
 
 import { useReleaseService } from './releaseService'
@@ -95,7 +94,7 @@ export const useReleaseStore = defineStore('release', () => {
   // Show toast if needed
   const shouldShowToast = computed(() => {
     // Only show on desktop version
-    if (!isElectron() || isCloud) {
+    if (!isDesktop || isCloud) {
       return false
     }
 
@@ -127,7 +126,7 @@ export const useReleaseStore = defineStore('release', () => {
   // Show red-dot indicator
   const shouldShowRedDot = computed(() => {
     // Only show on desktop version
-    if (!isElectron() || isCloud) {
+    if (!isDesktop || isCloud) {
       return false
     }
 
@@ -172,7 +171,7 @@ export const useReleaseStore = defineStore('release', () => {
   })
 
   const shouldShowPopup = computed(() => {
-    if (!isElectron() && !isCloud) {
+    if (!isDesktop && !isCloud) {
       return false
     }
 

src/platform/updates/components/ReleaseNotificationToast.test.ts

@@ -5,9 +5,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 import type { ReleaseNote } from '../common/releaseService'
 import ReleaseNotificationToast from './ReleaseNotificationToast.vue'
 
-interface TestWindow extends Window {
-  electronAPI?: Record<string, unknown>
-}
+const mockData = vi.hoisted(() => ({ isDesktop: false }))
 
 const { commandExecuteMock } = vi.hoisted(() => ({
   commandExecuteMock: vi.fn()
@@ -17,6 +15,14 @@ const { toastErrorHandlerMock } = vi.hoisted(() => ({
   toastErrorHandlerMock: vi.fn()
 }))
 
+vi.mock('@/platform/distribution/types', () => ({
+  isCloud: false,
+  isNightly: false,
+  get isDesktop() {
+    return mockData.isDesktop
+  }
+}))
+
 // Mock dependencies
 vi.mock('vue-i18n', () => ({
   useI18n: vi.fn(() => ({
@@ -105,6 +111,7 @@ describe('ReleaseNotificationToast', () => {
 
   beforeEach(() => {
     vi.clearAllMocks()
+    mockData.isDesktop = false
     // Reset store state
     mockReleaseStore.recentRelease = null
     mockReleaseStore.shouldShowToast = true // Force show for testing
@@ -183,7 +190,8 @@ describe('ReleaseNotificationToast', () => {
     )
   })
 
-  it('executes desktop updater flow when running in Electron', async () => {
+  it('executes desktop updater flow when running on desktop', async () => {
+    mockData.isDesktop = true
     mockReleaseStore.recentRelease = {
       version: '1.2.3',
       content: '# Test Release'
@@ -196,7 +204,6 @@ describe('ReleaseNotificationToast', () => {
       value: mockWindowOpen,
       writable: true
     })
-    ;(window as TestWindow).electronAPI = {}
 
     wrapper = mountComponent()
     await wrapper.vm.handleUpdate()
@@ -206,11 +213,10 @@ describe('ReleaseNotificationToast', () => {
     )
     expect(mockWindowOpen).not.toHaveBeenCalled()
     expect(toastErrorHandlerMock).not.toHaveBeenCalled()
-
-    delete (window as TestWindow).electronAPI
   })
 
-  it('shows an error toast if the desktop updater flow fails in Electron', async () => {
+  it('shows an error toast if the desktop updater flow fails on desktop', async () => {
+    mockData.isDesktop = true
     mockReleaseStore.recentRelease = {
       version: '1.2.3',
       content: '# Test Release'
@@ -224,15 +230,12 @@ describe('ReleaseNotificationToast', () => {
       value: mockWindowOpen,
       writable: true
     })
-    ;(window as TestWindow).electronAPI = {}
 
     wrapper = mountComponent()
     await wrapper.vm.handleUpdate()
 
     expect(toastErrorHandlerMock).toHaveBeenCalledWith(error)
     expect(mockWindowOpen).not.toHaveBeenCalled()
-
-    delete (window as TestWindow).electronAPI
   })
 
   it('calls handleShowChangelog when learn more link is clicked', async () => {

src/platform/updates/components/ReleaseNotificationToast.vue

@@ -72,7 +72,7 @@ import { useI18n } from 'vue-i18n'
 import { useErrorHandling } from '@/composables/useErrorHandling'
 import { useExternalLink } from '@/composables/useExternalLink'
 import { useCommandStore } from '@/stores/commandStore'
-import { isElectron } from '@/utils/envUtil'
+import { isDesktop } from '@/platform/distribution/types'
 import { formatVersionAnchor } from '@/utils/formatUtil'
 import { renderMarkdownToHtml } from '@/utils/markdownRendererUtil'
 
@@ -177,7 +177,7 @@ const handleLearnMore = () => {
 }
 
 const handleUpdate = async () => {
-  if (isElectron()) {
+  if (isDesktop) {
     try {
       await useCommandStore().execute('Comfy-Desktop.CheckForUpdates')
       dismissToast()