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/stores/aboutPanelStore.ts

@@ -2,9 +2,9 @@ import { defineStore } from 'pinia'
 import { computed } from 'vue'
 
 import { useExternalLink } from '@/composables/useExternalLink'
-import { isCloud } from '@/platform/distribution/types'
+import { isCloud, isDesktop } from '@/platform/distribution/types'
 import type { AboutPageBadge } from '@/types/comfy'
-import { electronAPI, isElectron } from '@/utils/envUtil'
+import { electronAPI } from '@/utils/envUtil'
 import { formatCommitHash } from '@/utils/formatUtil'
 
 import { useExtensionStore } from './extensionStore'
@@ -24,7 +24,7 @@ export const useAboutPanelStore = defineStore('aboutPanel', () => {
     // so the python server's API doesn't have the version info.
     {
       label: `ComfyUI ${
-        isElectron()
+        isDesktop
           ? 'v' + electronAPI().getComfyUIVersion()
           : formatCommitHash(coreVersion.value)
       }`,

src/stores/electronDownloadStore.ts

@@ -3,7 +3,8 @@ import type { DownloadState } from '@comfyorg/comfyui-electron-types'
 import { defineStore } from 'pinia'
 import { computed, ref } from 'vue'
 
-import { electronAPI, isElectron } from '@/utils/envUtil'
+import { isDesktop } from '@/platform/distribution/types'
+import { electronAPI } from '@/utils/envUtil'
 
 export interface ElectronDownload extends Pick<
   DownloadState,
@@ -17,35 +18,34 @@ export interface ElectronDownload extends Pick<
 /** Electron downloads store handler */
 export const useElectronDownloadStore = defineStore('downloads', () => {
   const downloads = ref<ElectronDownload[]>([])
-  const { DownloadManager } = electronAPI()
+  const DownloadManager = isDesktop ? electronAPI().DownloadManager : undefined
 
   const findByUrl = (url: string) =>
     downloads.value.find((download) => url === download.url)
 
   const initialize = async () => {
-    if (isElectron()) {
-      const allDownloads = await DownloadManager.getAllDownloads()
+    if (!isDesktop || !DownloadManager) return
 
-      for (const download of allDownloads) {
-        downloads.value.push(download)
+    const allDownloads = await DownloadManager.getAllDownloads()
+
+    for (const download of allDownloads) {
+      downloads.value.push(download)
+    }
+
+    DownloadManager.onDownloadProgress((data) => {
+      if (!findByUrl(data.url)) {
+        downloads.value.push(data)
       }
 
-      // ToDO: replace with ElectronDownload type
-      DownloadManager.onDownloadProgress((data) => {
-        if (!findByUrl(data.url)) {
-          downloads.value.push(data)
-        }
+      const download = findByUrl(data.url)
 
-        const download = findByUrl(data.url)
-
-        if (download) {
-          download.progress = data.progress
-          download.status = data.status
-          download.filename = data.filename
-          download.savePath = data.savePath
-        }
-      })
-    }
+      if (download) {
+        download.progress = data.progress
+        download.status = data.status
+        download.filename = data.filename
+        download.savePath = data.savePath
+      }
+    })
   }
 
   void initialize()
@@ -58,10 +58,10 @@ export const useElectronDownloadStore = defineStore('downloads', () => {
     url: string
     savePath: string
     filename: string
-  }) => DownloadManager.startDownload(url, savePath, filename)
-  const pause = (url: string) => DownloadManager.pauseDownload(url)
-  const resume = (url: string) => DownloadManager.resumeDownload(url)
-  const cancel = (url: string) => DownloadManager.cancelDownload(url)
+  }) => DownloadManager!.startDownload(url, savePath, filename)
+  const pause = (url: string) => DownloadManager!.pauseDownload(url)
+  const resume = (url: string) => DownloadManager!.resumeDownload(url)
+  const cancel = (url: string) => DownloadManager!.cancelDownload(url)
 
   return {
     downloads,

src/stores/systemStatsStore.test.ts

@@ -5,7 +5,8 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 import type { SystemStats } from '@/schemas/apiSchema'
 import { api } from '@/scripts/api'
 import { useSystemStatsStore } from '@/stores/systemStatsStore'
-import { isElectron } from '@/utils/envUtil'
+
+const mockData = vi.hoisted(() => ({ isDesktop: false }))
 
 // Mock the API
 vi.mock('@/scripts/api', () => ({
@@ -14,13 +15,13 @@ vi.mock('@/scripts/api', () => ({
   }
 }))
 
-// Mock the envUtil
-vi.mock('@/utils/envUtil', () => ({
-  isElectron: vi.fn()
+vi.mock('@/platform/distribution/types', () => ({
+  get isDesktop() {
+    return mockData.isDesktop
+  },
+  isCloud: false
 }))
 
-vi.mock('@/platform/distribution/types', () => ({ isCloud: false }))
-
 describe('useSystemStatsStore', () => {
   let store: ReturnType<typeof useSystemStatsStore>
 
@@ -161,9 +162,9 @@ describe('useSystemStatsStore', () => {
       expect(store.getFormFactor()).toBe('other')
     })
 
-    describe('desktop environment (Electron)', () => {
+    describe('desktop environment', () => {
       beforeEach(() => {
-        vi.mocked(isElectron).mockReturnValue(true)
+        mockData.isDesktop = true
       })
 
       it('should return "desktop-windows" for Windows desktop', () => {
@@ -239,9 +240,9 @@ describe('useSystemStatsStore', () => {
       })
     })
 
-    describe('git environment (non-Electron)', () => {
+    describe('git environment (non-desktop)', () => {
       beforeEach(() => {
-        vi.mocked(isElectron).mockReturnValue(false)
+        mockData.isDesktop = false
       })
 
       it('should return "git-windows" for Windows git', () => {
@@ -319,7 +320,7 @@ describe('useSystemStatsStore', () => {
 
     describe('case insensitive OS detection', () => {
       beforeEach(() => {
-        vi.mocked(isElectron).mockReturnValue(false)
+        mockData.isDesktop = false
       })
 
       it('should handle uppercase OS names', () => {

src/stores/systemStatsStore.ts

@@ -1,10 +1,9 @@
 import { useAsyncState } from '@vueuse/core'
 import { defineStore } from 'pinia'
 
-import { isCloud } from '@/platform/distribution/types'
+import { isCloud, isDesktop } from '@/platform/distribution/types'
 import type { SystemStats } from '@/schemas/apiSchema'
 import { api } from '@/scripts/api'
-import { isElectron } from '@/utils/envUtil'
 
 export const useSystemStatsStore = defineStore('systemStats', () => {
   const fetchSystemStatsData = async () => {
@@ -40,7 +39,6 @@ export const useSystemStatsStore = defineStore('systemStats', () => {
     }
 
     const os = systemStats.value.system.os.toLowerCase()
-    const isDesktop = isElectron()
 
     if (isDesktop) {
       if (os.includes('windows')) {

src/stores/workspace/bottomPanelStore.test.ts

@@ -48,8 +48,12 @@ vi.mock('@/stores/commandStore', () => ({
   })
 }))
 
-vi.mock('@/utils/envUtil', () => ({
-  isElectron: () => false
+const mockData = vi.hoisted(() => ({ isDesktop: false }))
+
+vi.mock('@/platform/distribution/types', () => ({
+  get isDesktop() {
+    return mockData.isDesktop
+  }
 }))
 
 describe('useBottomPanelStore', () => {

src/stores/workspace/bottomPanelStore.ts

@@ -3,10 +3,10 @@ import { computed, ref } from 'vue'
 
 import { useShortcutsTab } from '@/composables/bottomPanelTabs/useShortcutsTab'
 
+import { isDesktop } from '@/platform/distribution/types'
 import { useCommandStore } from '@/stores/commandStore'
 import type { ComfyExtension } from '@/types/comfy'
 import type { BottomPanelExtension } from '@/types/extensionTypes'
-import { isElectron } from '@/utils/envUtil'
 
 type PanelType = 'terminal' | 'shortcuts'
 
@@ -138,7 +138,7 @@ export const useBottomPanelStore = defineStore('bottomPanel', () => {
         const { useLogsTerminalTab, useCommandTerminalTab } =
           await import('@/composables/bottomPanelTabs/useTerminalTabs')
         registerBottomPanelTab(useLogsTerminalTab())
-        if (isElectron()) {
+        if (isDesktop) {
           registerBottomPanelTab(useCommandTerminalTab())
         }
       } catch (error) {