fix: referral system — stop cabinet redirect to Telegram, fix deep link code handling

- Remove redirect to Telegram bot when email auth disabled + referral code present
  (cabinet links should stay on cabinet, bot links should go to bot)
- Remove referral_code from deep link auth (existing users can't get referrals)
- Don't consume referralCode in deep link path — leave it in localStorage for
  OIDC/widget auth methods that actually send it to the backend
- Consume campaign slug once into ref to survive retries (codesConsumedRef pattern)
- Update loginWithDeepLink to only accept (token, campaignSlug) — no referralCode
- Update pollDeepLinkToken API to match backend schema change

src/api/auth.ts

@@ -290,7 +290,7 @@ export const authApi = {
     return response.data;
   },
 
-  pollDeepLinkToken: async (token: string): Promise<AuthResponse> => {
+  pollDeepLinkToken: async (token: string, campaignSlug?: string | null): Promise<AuthResponse> => {
     // validateStatus: only treat 200 as success.
     // Server returns 202 for "pending" and 410 for "expired" —
     // these must reject so the polling catch-block can handle them.
@@ -299,7 +299,7 @@ export const authApi = {
     // which triggers checkAdminStatus() → 401 → safeRedirectToLogin() → infinite reload.
     const response = await apiClient.post<AuthResponse>(
       '/cabinet/auth/deeplink/poll',
-      { token },
+      { token, campaign_slug: campaignSlug || undefined },
       { validateStatus: (status) => status === 200 },
     );
     return response.data;