fix: use authenticated API for remote config polling (#8266)

## Summary
- Fixes remote config polling to use authenticated API
- Consolidates `loadRemoteConfig` into `refreshRemoteConfig` with auth
control
- Adds unit tests for both auth modes

## Problem
The cloud extension's polling interval was using unauthenticated
`fetch`, causing it to receive only default feature flags instead of
user-specific configurations.

**Root cause:**
1. Bootstrap called `loadRemoteConfig()` (raw `fetch`, no auth) -
correct, auth not initialized yet
2. Extension watch called `refreshRemoteConfig()` (`api.fetchApi`, with
auth) - correct
3. Extension interval called `loadRemoteConfig()` (raw `fetch`, no auth)
- **bug**

## Solution
- Consolidate into single `refreshRemoteConfig()` with optional
`useAuth` parameter (defaults to `true`)
- Bootstrap: `refreshRemoteConfig({ useAuth: false })`
- Polling: `refreshRemoteConfig()` (authenticated by default)

## Test Plan
- Unit tests verify both auth modes
- `pnpm typecheck`, `pnpm lint`, `pnpm test:unit` all pass

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8266-fix-use-authenticated-API-for-remote-config-polling-2f16d73d3650817ea7b0e3a7e3ccf12a)
by [Unito](https://www.unito.io)

src/extensions/core/cloudRemoteConfig.ts

@@ -2,7 +2,6 @@ import { watchDebounced } from '@vueuse/core'
 
 import { useCurrentUser } from '@/composables/auth/useCurrentUser'
 import { useSubscription } from '@/platform/cloud/subscription/composables/useSubscription'
-import { loadRemoteConfig } from '@/platform/remoteConfig/remoteConfig'
 import { refreshRemoteConfig } from '@/platform/remoteConfig/refreshRemoteConfig'
 import { useExtensionService } from '@/services/extensionService'
 
@@ -26,7 +25,7 @@ useExtensionService().registerExtension({
       { debounce: 256, immediate: true }
     )
 
-    // Poll for config updates every 10 minutes
-    setInterval(() => void loadRemoteConfig(), 600_000)
+    // Poll for config updates every 10 minutes (with auth)
+    setInterval(() => void refreshRemoteConfig(), 600_000)
   }
 })