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;

src/components/TelegramLoginButton.tsx

@@ -6,6 +6,7 @@ import { brandingApi, type TelegramWidgetConfig } from '../api/branding';
 import { authApi } from '../api/auth';
 import { useAuthStore } from '../store/auth';
 import { useNavigate } from 'react-router';
+import { consumeCampaignSlug } from '../utils/campaign';
 
 interface TelegramLoginButtonProps {
   referralCode?: string;
@@ -34,6 +35,10 @@ export default function TelegramLoginButton({ referralCode }: TelegramLoginButto
 
   const loginWithDeepLink = useAuthStore((s) => s.loginWithDeepLink);
 
+  // Capture campaign slug once on mount (before any retry clears it)
+  const capturedCampaignRef = useRef<string | null>(null);
+  const codesConsumedRef = useRef(false);
+
   const { data: widgetConfig } = useQuery<TelegramWidgetConfig>({
     queryKey: ['telegram-widget-config'],
     queryFn: brandingApi.getTelegramWidgetConfig,
@@ -239,6 +244,17 @@ export default function TelegramLoginButton({ referralCode }: TelegramLoginButto
     }
 
     try {
+      // Consume campaign slug ONCE (first call only).
+      // Clears localStorage on first call, so subsequent retries reuse the ref.
+      // Note: referral code is NOT consumed here — deep link auth is for existing
+      // bot users where referrals don't apply. Leaving it in localStorage allows
+      // other auth methods (OIDC, widget) to pick it up if the user switches paths.
+      if (!codesConsumedRef.current) {
+        capturedCampaignRef.current = consumeCampaignSlug();
+        codesConsumedRef.current = true;
+      }
+      const capturedCampaign = capturedCampaignRef.current;
+
       const response = await authApi.requestDeepLinkToken();
       const { token, bot_username, expires_in } = response;
       setDeepLinkToken(token);
@@ -249,7 +265,8 @@ export default function TelegramLoginButton({ referralCode }: TelegramLoginButto
       const poll = async () => {
         if (!mountedRef.current) return;
         try {
-          await loginWithDeepLink(token);
+          // Deep link auth is for existing bot users — only campaign_slug applies
+          await loginWithDeepLink(token, capturedCampaign);
           // Success — auth store is updated, navigate
           if (expireTimeoutRef.current) {
             clearTimeout(expireTimeoutRef.current);

src/pages/Login.tsx

@@ -22,7 +22,7 @@ import LanguageSwitcher from '../components/LanguageSwitcher';
 import TelegramLoginButton from '../components/TelegramLoginButton';
 import OAuthProviderIcon from '../components/OAuthProviderIcon';
 import { saveOAuthState } from '../utils/oauth';
-import { consumeReferralCode, getPendingReferralCode } from '../utils/referral';
+import { getPendingReferralCode } from '../utils/referral';
 
 export default function Login() {
   const { t } = useTranslation();
@@ -146,16 +146,6 @@ export default function Login() {
     }
   };
 
-  const botUsername = import.meta.env.VITE_TELEGRAM_BOT_USERNAME || '';
-
-  // If email auth is disabled but user came with ref param, redirect to bot
-  useEffect(() => {
-    if (referralCode && emailAuthConfig?.enabled === false && botUsername) {
-      consumeReferralCode();
-      window.location.href = `https://t.me/${botUsername}?start=${encodeURIComponent(referralCode)}`;
-    }
-  }, [referralCode, emailAuthConfig, botUsername]);
-
   const appName = branding ? branding.name : import.meta.env.VITE_APP_NAME || 'VPN';
   const appLogo = branding?.logo_letter || import.meta.env.VITE_APP_LOGO || 'V';
   const logoUrl = branding ? brandingApi.getLogoUrl(branding) : null;

src/store/auth.ts

@@ -45,7 +45,7 @@ interface AuthState {
     state: string,
     deviceId?: string | null,
   ) => Promise<void>;
-  loginWithDeepLink: (token: string) => Promise<void>;
+  loginWithDeepLink: (token: string, campaignSlug?: string | null) => Promise<void>;
   registerWithEmail: (
     email: string,
     password: string,
@@ -322,8 +322,8 @@ export const useAuthStore = create<AuthState>()(
         await get().checkAdminStatus();
       },
 
-      loginWithDeepLink: async (token) => {
-        const response = await authApi.pollDeepLinkToken(token);
+      loginWithDeepLink: async (token, campaignSlug) => {
+        const response = await authApi.pollDeepLinkToken(token, campaignSlug);
         if (!response.access_token || !response.refresh_token) {
           throw new Error('Invalid auth response: missing tokens');
         }