fix(grok): route OAuth subscriptions through CLI proxy

frontend/src/composables/__tests__/useGrokOAuth.spec.ts

@@ -53,3 +53,20 @@ describe('useGrokOAuth.exchangeAuthCode', () => {
     )
   })
 })
+
+describe('useGrokOAuth.buildCredentials', () => {
+  it('persists the Grok CLI subscription proxy for OAuth inference', () => {
+    const oauth = useGrokOAuth()
+
+    const credentials = oauth.buildCredentials({
+      access_token: 'access-token',
+      token_type: 'Bearer',
+      expires_at: 1_900_000_000,
+      client_id: 'client-id',
+      scope: 'openid grok-cli:access',
+      email: 'grok@example.com'
+    })
+
+    expect(credentials.base_url).toBe('https://cli-chat-proxy.grok.com/v1')
+  })
+})

frontend/src/composables/useGrokOAuth.ts

@@ -122,7 +122,8 @@ export function useGrokOAuth() {
       scope: tokenInfo.scope,
       email: tokenInfo.email,
       subscription_tier: tokenInfo.subscription_tier,
-      entitlement_status: tokenInfo.entitlement_status
+      entitlement_status: tokenInfo.entitlement_status,
+      base_url: 'https://cli-chat-proxy.grok.com/v1'
     }
     if (tokenInfo.refresh_token) credentials.refresh_token = tokenInfo.refresh_token
     if (tokenInfo.id_token) credentials.id_token = tokenInfo.id_token