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/components/TopMenuSection.test.ts

@@ -18,9 +18,8 @@ import { useCommandStore } from '@/stores/commandStore'
 import { useExecutionStore } from '@/stores/executionStore'
 import { TaskItemImpl, useQueueStore } from '@/stores/queueStore'
 import { useSidebarTabStore } from '@/stores/workspace/sidebarTabStore'
-import { isElectron } from '@/utils/envUtil'
 
-const mockData = vi.hoisted(() => ({ isLoggedIn: false }))
+const mockData = vi.hoisted(() => ({ isLoggedIn: false, isDesktop: false }))
 
 vi.mock('@/composables/auth/useCurrentUser', () => ({
   useCurrentUser: () => {
@@ -30,7 +29,13 @@ vi.mock('@/composables/auth/useCurrentUser', () => ({
   }
 }))
 
-vi.mock('@/utils/envUtil')
+vi.mock('@/platform/distribution/types', () => ({
+  isCloud: false,
+  isNightly: false,
+  get isDesktop() {
+    return mockData.isDesktop
+  }
+}))
 vi.mock('@/stores/firebaseAuthStore', () => ({
   useFirebaseAuthStore: vi.fn(() => ({
     currentUser: null,
@@ -107,6 +112,8 @@ describe('TopMenuSection', () => {
   beforeEach(() => {
     vi.resetAllMocks()
     localStorage.clear()
+    mockData.isDesktop = false
+    mockData.isLoggedIn = false
   })
 
   describe('authentication state', () => {
@@ -129,7 +136,7 @@ describe('TopMenuSection', () => {
 
       describe('on desktop platform', () => {
         it('should display LoginButton and not display CurrentUserButton', () => {
-          vi.mocked(isElectron).mockReturnValue(true)
+          mockData.isDesktop = true
           const wrapper = createWrapper()
           expect(wrapper.findComponent(LoginButton).exists()).toBe(true)
           expect(wrapper.findComponent(CurrentUserButton).exists()).toBe(false)

src/components/TopMenuSection.vue

@@ -153,7 +153,7 @@ import { useQueueStore, useQueueUIStore } from '@/stores/queueStore'
 import { useRightSidePanelStore } from '@/stores/workspace/rightSidePanelStore'
 import { useSidebarTabStore } from '@/stores/workspace/sidebarTabStore'
 import { useWorkspaceStore } from '@/stores/workspaceStore'
-import { isElectron } from '@/utils/envUtil'
+import { isDesktop } from '@/platform/distribution/types'
 import { useConflictAcknowledgment } from '@/workbench/extensions/manager/composables/useConflictAcknowledgment'
 import { useManagerState } from '@/workbench/extensions/manager/composables/useManagerState'
 import { ManagerTab } from '@/workbench/extensions/manager/types/comfyManagerTypes'
@@ -163,7 +163,6 @@ const workspaceStore = useWorkspaceStore()
 const rightSidePanelStore = useRightSidePanelStore()
 const managerState = useManagerState()
 const { isLoggedIn } = useCurrentUser()
-const isDesktop = isElectron()
 const { t, n } = useI18n()
 const { toastErrorHandler } = useErrorHandling()
 const commandStore = useCommandStore()

src/components/bottomPanel/tabs/terminal/BaseTerminal.test.ts

@@ -55,10 +55,17 @@ vi.mock('@/composables/bottomPanelTabs/useTerminal', () => ({
 }))
 
 vi.mock('@/utils/envUtil', () => ({
-  isElectron: vi.fn(() => false),
   electronAPI: vi.fn(() => null)
 }))
 
+const mockData = vi.hoisted(() => ({ isDesktop: false }))
+
+vi.mock('@/platform/distribution/types', () => ({
+  get isDesktop() {
+    return mockData.isDesktop
+  }
+}))
+
 // Mock clipboard API
 Object.defineProperty(navigator, 'clipboard', {
   value: {

src/components/bottomPanel/tabs/terminal/BaseTerminal.vue

@@ -35,7 +35,8 @@ import { useI18n } from 'vue-i18n'
 
 import Button from '@/components/ui/button/Button.vue'
 import { useTerminal } from '@/composables/bottomPanelTabs/useTerminal'
-import { electronAPI, isElectron } from '@/utils/envUtil'
+import { electronAPI } from '@/utils/envUtil'
+import { isDesktop } from '@/platform/distribution/types'
 import { cn } from '@/utils/tailwindUtil'
 
 const { t } = useI18n()
@@ -85,7 +86,7 @@ const showContextMenu = (event: MouseEvent) => {
   electronAPI()?.showContextMenu({ type: 'text' })
 }
 
-if (isElectron()) {
+if (isDesktop) {
   useEventListener(terminalEl, 'contextmenu', showContextMenu)
 }
 

src/components/dialog/content/MissingModelsWarning.vue

@@ -13,7 +13,7 @@
   </div>
   <ListBox :options="missingModels" class="comfy-missing-models">
     <template #option="{ option }">
-      <Suspense v-if="isElectron()">
+      <Suspense v-if="isDesktop">
         <ElectronFileDownload
           :url="option.url"
           :label="option.label"
@@ -40,7 +40,7 @@ import ElectronFileDownload from '@/components/common/ElectronFileDownload.vue'
 import FileDownload from '@/components/common/FileDownload.vue'
 import NoResultsPlaceholder from '@/components/common/NoResultsPlaceholder.vue'
 import { useSettingStore } from '@/platform/settings/settingStore'
-import { isElectron } from '@/utils/envUtil'
+import { isDesktop } from '@/platform/distribution/types'
 
 // TODO: Read this from server internal API rather than hardcoding here
 // as some installations may wish to use custom sources

src/components/helpcenter/HelpCenterMenuContent.vue

@@ -159,13 +159,13 @@ import { useI18n } from 'vue-i18n'
 
 import PuzzleIcon from '@/components/icons/PuzzleIcon.vue'
 import { useExternalLink } from '@/composables/useExternalLink'
-import { isCloud } from '@/platform/distribution/types'
+import { isCloud, isDesktop } from '@/platform/distribution/types'
 import { useSettingStore } from '@/platform/settings/settingStore'
 import { useTelemetry } from '@/platform/telemetry'
 import type { ReleaseNote } from '@/platform/updates/common/releaseService'
 import { useReleaseStore } from '@/platform/updates/common/releaseStore'
 import { useCommandStore } from '@/stores/commandStore'
-import { electronAPI, isElectron } from '@/utils/envUtil'
+import { electronAPI } from '@/utils/envUtil'
 import { formatVersionAnchor } from '@/utils/formatUtil'
 import { useConflictAcknowledgment } from '@/workbench/extensions/manager/composables/useConflictAcknowledgment'
 import { useManagerState } from '@/workbench/extensions/manager/composables/useManagerState'
@@ -241,7 +241,7 @@ const moreItems = computed<MenuItem[]>(() => {
       key: 'desktop-guide',
       type: 'item',
       label: t('helpCenter.desktopUserGuide'),
-      visible: isElectron(),
+      visible: isDesktop,
       action: () => {
         trackResourceClick('docs', true)
         openExternalLink(
@@ -257,7 +257,7 @@ const moreItems = computed<MenuItem[]>(() => {
       key: 'dev-tools',
       type: 'item',
       label: t('helpCenter.openDevTools'),
-      visible: isElectron(),
+      visible: isDesktop,
       action: () => {
         openDevTools()
         emit('close')
@@ -266,13 +266,13 @@ const moreItems = computed<MenuItem[]>(() => {
     {
       key: 'divider-1',
       type: 'divider',
-      visible: isElectron()
+      visible: isDesktop
     },
     {
       key: 'reinstall',
       type: 'item',
       label: t('helpCenter.reinstall'),
-      visible: isElectron(),
+      visible: isDesktop,
       action: () => {
         onReinstall()
         emit('close')
@@ -374,7 +374,7 @@ const menuItems = computed<MenuItem[]>(() => {
     })
   }
   // Update ComfyUI - only for non-desktop, non-cloud with new manager UI
-  if (!isElectron() && !isCloud && isNewManagerUI.value) {
+  if (!isDesktop && !isCloud && isNewManagerUI.value) {
     items.push({
       key: 'update-comfyui',
       type: 'item',
@@ -551,13 +551,13 @@ const onSubmenuLeave = (): void => {
 }
 
 const openDevTools = (): void => {
-  if (isElectron()) {
+  if (isDesktop) {
     electronAPI().openDevTools()
   }
 }
 
 const onReinstall = (): void => {
-  if (isElectron()) {
+  if (isDesktop) {
     void electronAPI().reinstall()
   }
 }

src/components/sidebar/tabs/ModelLibrarySidebarTab.vue

@@ -35,7 +35,7 @@
       </div>
     </template>
     <template #body>
-      <ElectronDownloadItems v-if="isElectron()" />
+      <ElectronDownloadItems v-if="isDesktop" />
 
       <Divider type="dashed" class="m-2" />
       <TreeExplorer
@@ -69,7 +69,7 @@ import type { ComfyModelDef, ModelFolder } from '@/stores/modelStore'
 import { ResourceState, useModelStore } from '@/stores/modelStore'
 import { useModelToNodeStore } from '@/stores/modelToNodeStore'
 import type { TreeExplorerNode, TreeNode } from '@/types/treeExplorerTypes'
-import { isElectron } from '@/utils/envUtil'
+import { isDesktop } from '@/platform/distribution/types'
 import { buildTree } from '@/utils/treeUtil'
 
 const modelStore = useModelStore()

src/components/topbar/WorkflowTabs.vue

@@ -115,7 +115,7 @@ import type { ComfyWorkflow } from '@/platform/workflow/management/stores/workfl
 import { useWorkflowStore } from '@/platform/workflow/management/stores/workflowStore'
 import { useCommandStore } from '@/stores/commandStore'
 import { useWorkspaceStore } from '@/stores/workspaceStore'
-import { isElectron } from '@/utils/envUtil'
+import { isDesktop } from '@/platform/distribution/types'
 import { whileMouseDown } from '@/utils/mouseDownUtil'
 
 import WorkflowOverflowMenu from './WorkflowOverflowMenu.vue'
@@ -148,8 +148,6 @@ const showOverflowArrows = ref(false)
 const leftArrowEnabled = ref(false)
 const rightArrowEnabled = ref(false)
 
-const isDesktop = isElectron()
-
 const workflowToOption = (workflow: ComfyWorkflow): WorkflowOption => ({
   value: workflow.path,
   workflow