add session cookie auth on cloud dist (#6295)

## Summary

Implemented cookie-based session authentication for cloud distribution,
replacing service worker approach with extension-based lifecycle hooks.

## Changes

- **What**: Added session cookie management via [extension
hooks](https://docs.comfy.org/comfyui/extensions) for login, token
refresh, and logout events
- **Architecture**: DDD-compliant structure with platform layer
(`src/platform/auth/session/`) and cloud-gated extension
- **New Extension Hooks**: `onAuthTokenRefreshed()` and
`onAuthUserLogout()` in [ComfyExtension
interface](src/types/comfy.ts:220-232)

```mermaid
sequenceDiagram
    participant User
    participant Firebase
    participant Extension
    participant Backend

    User->>Firebase: Login
    Firebase->>Extension: onAuthUserResolved
    Extension->>Backend: POST /auth/session (with JWT)
    Backend-->>Extension: Set-Cookie

    Firebase->>Firebase: Token Refresh
    Firebase->>Extension: onAuthTokenRefreshed
    Extension->>Backend: POST /auth/session (with new JWT)
    Backend-->>Extension: Update Cookie

    User->>Firebase: Logout
    Firebase->>Extension: onAuthUserLogout (user null)
    Extension->>Backend: DELETE /auth/session
    Backend-->>Extension: Clear Cookie
```

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6295-add-session-cookie-auth-on-cloud-dist-2986d73d365081868c56e5be1ad0d0d4)
by [Unito](https://www.unito.io)

src/services/extensionService.ts

@@ -80,6 +80,20 @@ export const useExtensionService = () => {
         void extension.onAuthUserResolved?.(user, app)
       })
     }
+
+    if (extension.onAuthTokenRefreshed) {
+      const { onTokenRefreshed } = useCurrentUser()
+      onTokenRefreshed(() => {
+        void extension.onAuthTokenRefreshed?.()
+      })
+    }
+
+    if (extension.onAuthUserLogout) {
+      const { onUserLogout } = useCurrentUser()
+      onUserLogout(() => {
+        void extension.onAuthUserLogout?.()
+      })
+    }
   }
 
   /**