Add distribution detection pattern (#6028)

## Summary

Establishes distribution-specific code pattern using compile-time
constants and dead code elimination. Demonstrates with Help Center by
hiding extension manager and update buttons in cloud distribution.

Below commentary makes assumption that minifcation and tree-shaking is
enabled (which isn't true yet, but will be eventually).

## Changes

- **What**: Added `src/platform/distribution/types.ts` with distribution
detection via `__DISTRIBUTION__` variable
- **Build**: Vite replaces `__DISTRIBUTION__` at build time using
environment variables
- **Tree-shaking**: All code not relevant to target distribution is
DCR'd and eliminated from bundle
- **Example**: Help Center hides "Manager Extension" menu item and
"Update" buttons in cloud builds

## Pattern

This PR defines a `__DISTRIBUTION__` variable which gets replaced at
build time by Vite using environment variables. All code not relevant to
the given distribution is then DCR'd and tree-shaken.

For simple cases (like this Help Center PR), import `isCloud` and use
compile-time conditionals:

```typescript
import { isCloud } from '@/platform/distribution/types'

if (!isCloud) {
  items.push({
    key: 'manager',
    action: async () => {
      await useManagerState().openManager({ ... })
    }
  })
}
```

The code is DCR'd at build time so there's zero runtime overhead - we
don't even incur the `if (isCloud)` cost because Terser eliminates it.

For complex services later, we'll add interfaces and use an index.ts
that exports different implementations under the same alias per
distribution. It will resemble a DI container but simpler since we don't
need runtime discovery like backend devs do. This guarantees types and
makes testing easier.

Example for services:
```typescript
// src/platform/storage/index.ts
import { isCloud } from '@/platform/distribution/types'

if (isCloud) {
  export { CloudStorage as StorageService } from './cloud'
} else {
  export { LocalStorage as StorageService } from './local'
}
```

Example for component variants:
```typescript
// src/components/downloads/index.ts
import { isCloud } from '@/platform/distribution/types'

if (isCloud) {
  export { default as DownloadButton } from './DownloadButton.cloud.vue'
} else {
  export { default as DownloadButton } from './DownloadButton.desktop.vue'
}
```

## Implementation Details

Distribution types (`src/platform/distribution/types.ts`):
```typescript
type Distribution = 'desktop' | 'localhost' | 'cloud'

declare global {
  const __DISTRIBUTION__: Distribution
}

const DISTRIBUTION: Distribution = __DISTRIBUTION__
export const isCloud = DISTRIBUTION === 'cloud'
```

Vite configuration adds the define:
```typescript
const DISTRIBUTION = (process.env.DISTRIBUTION || 'localhost') as
  | 'desktop'
  | 'localhost'
  | 'cloud'

export default defineConfig({
  define: {
    __DISTRIBUTION__: JSON.stringify(DISTRIBUTION)
  }
})
```

## Build Commands

```bash
pnpm build                      # localhost (default)
DISTRIBUTION=cloud pnpm build   # cloud
DISTRIBUTION=desktop pnpm build # desktop
```

## Future Applications

This pattern can be used with auth or telemetry services - which will
guarantee all the telemetry code, for example, is not even in the code
distributed in OSS Comfy whatsoever while still being able to develop
off `main`.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6028-Add-distribution-detection-pattern-28a6d73d365081b08767d395472cd1bc)
by [Unito](https://www.unito.io)

src/components/helpcenter/HelpCenterMenuContent.vue

@@ -135,6 +135,7 @@ import type { CSSProperties, Component } from 'vue'
 import { useI18n } from 'vue-i18n'
 
 import PuzzleIcon from '@/components/icons/PuzzleIcon.vue'
+import { isCloud } from '@/platform/distribution/types'
 import { useSettingStore } from '@/platform/settings/settingStore'
 import type { ReleaseNote } from '@/platform/updates/common/releaseService'
 import { useReleaseStore } from '@/platform/updates/common/releaseStore'
@@ -265,7 +266,7 @@ const moreMenuItem = computed(() =>
 )
 
 const menuItems = computed<MenuItem[]>(() => {
-  return [
+  const items: MenuItem[] = [
     {
       key: 'docs',
       type: 'item',
@@ -305,8 +306,12 @@ const menuItems = computed<MenuItem[]>(() => {
         void commandStore.execute('Comfy.ContactSupport')
         emit('close')
       }
-    },
-    {
+    }
+  ]
+
+  // Extension manager - only in non-cloud distributions
+  if (!isCloud) {
+    items.push({
       key: 'manager',
       type: 'item',
       icon: PuzzleIcon,
@@ -319,17 +324,20 @@ const menuItems = computed<MenuItem[]>(() => {
         })
         emit('close')
       }
-    },
-    {
-      key: 'more',
-      type: 'item',
-      icon: '',
-      label: t('helpCenter.more'),
-      visible: hasVisibleMoreItems.value,
-      action: () => {}, // No action for more item
-      items: moreItems.value
-    }
-  ]
+    })
+  }
+
+  items.push({
+    key: 'more',
+    type: 'item',
+    icon: '',
+    label: t('helpCenter.more'),
+    visible: hasVisibleMoreItems.value,
+    action: () => {}, // No action for more item
+    items: moreItems.value
+  })
+
+  return items
 })
 
 // Utility Functions
@@ -420,6 +428,9 @@ const formatReleaseDate = (dateString?: string): string => {
 }
 
 const shouldShowUpdateButton = (release: ReleaseNote): boolean => {
+  // Hide update buttons in cloud distribution
+  if (isCloud) return false
+
   return (
     releaseStore.shouldShowUpdateButton &&
     release === releaseStore.recentReleases[0]

src/platform/distribution/types.ts

@@ -0,0 +1,18 @@
+/**
+ * Distribution types and compile-time constants for managing
+ * multi-distribution builds (Desktop, Localhost, Cloud)
+ */
+
+type Distribution = 'desktop' | 'localhost' | 'cloud'
+
+declare global {
+  const __DISTRIBUTION__: Distribution
+}
+
+/** Current distribution - replaced at compile time */
+const DISTRIBUTION: Distribution = __DISTRIBUTION__
+
+/** Distribution type checks */
+// const isDesktop = DISTRIBUTION === 'desktop'
+// const isLocalhost = DISTRIBUTION === 'localhost'
+export const isCloud = DISTRIBUTION === 'cloud'

tsconfig.json

@@ -58,6 +58,7 @@
     "src/types/**/*.d.ts",
     "tailwind.config.ts",
     "tests-ui/**/*",
+    "vite.config.mts",
     "vitest.config.ts",
     // "vitest.setup.ts",
   ]

vite.config.mts

@@ -24,6 +24,11 @@ const DISABLE_VUE_PLUGINS = process.env.DISABLE_VUE_PLUGINS === 'true'
 const DEV_SERVER_COMFYUI_URL =
   process.env.DEV_SERVER_COMFYUI_URL || 'http://127.0.0.1:8188'
 
+const DISTRIBUTION = (process.env.DISTRIBUTION || 'localhost') as
+  | 'desktop'
+  | 'localhost'
+  | 'cloud'
+
 export default defineConfig({
   base: '',
   server: {
@@ -195,7 +200,8 @@ export default defineConfig({
     __SENTRY_DSN__: JSON.stringify(process.env.SENTRY_DSN || ''),
     __ALGOLIA_APP_ID__: JSON.stringify(process.env.ALGOLIA_APP_ID || ''),
     __ALGOLIA_API_KEY__: JSON.stringify(process.env.ALGOLIA_API_KEY || ''),
-    __USE_PROD_CONFIG__: process.env.USE_PROD_CONFIG === 'true'
+    __USE_PROD_CONFIG__: process.env.USE_PROD_CONFIG === 'true',
+    __DISTRIBUTION__: JSON.stringify(DISTRIBUTION)
   },
 
   resolve: {