Remove deprecated /register route and fix referral code persistence

app/_layout.tsx

@@ -301,13 +301,6 @@ export default Sentry.wrap(function RootLayout() {
                             animation: 'none',
                           }}
                         />
-                        <Stack.Screen
-                          name="register"
-                          options={{
-                            headerShown: false,
-                            animation: 'none',
-                          }}
-                        />
                         <Stack.Screen
                           name="welcome"
                           options={{

app/signup/email.tsx

@@ -20,7 +20,8 @@ import { useDimension } from '@/hooks/useDimension';
 import { track } from '@/lib/analytics';
 import { emailExists, initSignupOtp } from '@/lib/api';
 import { getAsset } from '@/lib/assets';
-import { detectAndSaveReferralCode, getReferralCodeForSignup } from '@/lib/utils/referral';
+import { getReferralCodeForSignup } from '@/lib/utils/referral';
+import { useAttributionStore } from '@/store/useAttributionStore';
 import { useSignupFlowStore } from '@/store/useSignupFlowStore';
 
 const emailSchema = z.object({
@@ -67,20 +68,6 @@ export default function SignupEmail() {
 
   const watchedEmail = watch('email');
 
-  // Detect and save referral code from URL on mount
-  useEffect(() => {
-    // Wait for store hydration before any actions
-    if (!_hasHydrated) return;
-    try {
-      const detectedReferralCode = detectAndSaveReferralCode();
-      if (detectedReferralCode) {
-        console.warn('Referral code detected from URL:', detectedReferralCode);
-      }
-    } catch (err) {
-      console.warn('Error detecting referral code:', err);
-    }
-  }, [_hasHydrated]);
-
   // Clear rate limit error when email changes
   useEffect(() => {
     // Wait for store hydration before any actions
@@ -90,14 +77,24 @@ export default function SignupEmail() {
     }
   }, [_hasHydrated, watchedEmail, email, rateLimitError, setRateLimitError]);
 
-  // Reset flow state on mount (only after hydration completes)
-  // Note: Using getState() to avoid dependency on reset function reference
-  // which can change during Zustand hydration and cause infinite loops
+  // Reset flow state on mount while preserving referral code
+  // Attribution hook captures referral code at root - we preserve it here
   useEffect(() => {
-    // Wait for store hydration before resetting to prevent race conditions
+    // Wait for store hydration before any actions
     if (!_hasHydrated) return;
+
+    // Capture referral code BEFORE reset (from attribution or referral store)
+    const existingReferral = getReferralCodeForSignup();
+
+    // Reset the signup flow store
     useSignupFlowStore.getState().reset();
-  }, [_hasHydrated]);
+
+    // Restore referral code AFTER reset to prevent data loss
+    if (existingReferral) {
+      setReferralCode(existingReferral);
+      console.warn('✅ Referral code preserved after reset:', existingReferral);
+    }
+  }, [_hasHydrated, setReferralCode]);
 
   // Wait for store hydration before rendering
   if (!_hasHydrated) {
@@ -130,10 +127,15 @@ export default function SignupEmail() {
       setMarketingConsent(data.marketingConsent);
       setLastOtpSentAt(Date.now());
 
-      // Store referral code if present
-      const storedReferralCode = getReferralCodeForSignup() || '';
+      // Store referral code with multi-source fallback for reliability
+      // Priority: URL params > referral store > attribution store
+      const storedReferralCode =
+        getReferralCodeForSignup() ||
+        useAttributionStore.getState().attributionData.referral_code ||
+        '';
       if (storedReferralCode) {
         setReferralCode(storedReferralCode);
+        console.warn('✅ Referral code saved to signup flow:', storedReferralCode);
       }
 
       track(TRACKING_EVENTS.EMAIL_SUBMITTED, {

constants/path.ts

@@ -2,7 +2,6 @@ import { Href, Route } from 'expo-router';
 
 type Path = {
   ONBOARDING: Href;
-  REGISTER: Route;
   WELCOME: Href;
   HOME: Href;
   // Email-first signup flow
@@ -42,7 +41,6 @@ type Path = {
 
 export const path: Path = {
   ONBOARDING: '/onboarding',
-  REGISTER: '/register',
   WELCOME: '/welcome',
   HOME: '/',
   // Email-first signup flow

hooks/useAttributionInitialization.ts

@@ -5,6 +5,7 @@ import { Platform } from 'react-native';
 
 import { formatAttributionForLogging, getCurrentURL, getReferrer } from '@/lib/attribution';
 import { useAttributionStore } from '@/store/useAttributionStore';
+import { useReferralStore } from '@/store/useReferralStore';
 
 /**
  * Hook to initialize attribution tracking on app launch
@@ -27,14 +28,16 @@ import { useAttributionStore } from '@/store/useAttributionStore';
 export const useAttributionInitialization = () => {
   const attributionStore = useAttributionStore();
   const _hasHydrated = useAttributionStore(state => state._hasHydrated);
+  const _referralHasHydrated = useReferralStore(state => state._hasHydrated);
   const hasInitialized = useRef(false);
   const subscriptionRef = useRef<ReturnType<typeof Linking.addEventListener> | null>(null);
 
   useEffect(() => {
-    // Wait for store hydration before initialization
+    // Wait for BOTH stores' hydration before initialization
     // This ensures we don't overwrite existing first-touch attribution
-    if (!_hasHydrated) {
-      console.warn('Waiting for attribution store hydration...');
+    // and prevents referral code sync failures
+    if (!_hasHydrated || !_referralHasHydrated) {
+      console.warn('Waiting for attribution and referral store hydration...');
       return;
     }
 
@@ -60,6 +63,26 @@ export const useAttributionInitialization = () => {
           if (currentUrl) {
             const captured = attributionStore.captureFromURL(currentUrl);
 
+            // Verify referral code sync if present
+            if (captured && captured.referral_code) {
+              const verifyReferral = useReferralStore.getState().referralCode;
+              console.warn('✅ Referral code captured:', {
+                code: captured.referral_code,
+                synced: captured.referral_code === verifyReferral,
+              });
+
+              if (captured.referral_code !== verifyReferral) {
+                console.error('❌ REFERRAL SYNC FAILED - stores out of sync!');
+                Sentry.captureMessage('Referral code sync mismatch', {
+                  level: 'error',
+                  extra: {
+                    captured: captured.referral_code,
+                    inReferralStore: verifyReferral,
+                  },
+                });
+              }
+            }
+
             // Enrich with HTTP referrer if available
             if (captured && referrer) {
               attributionStore.updateAttribution({
@@ -134,5 +157,5 @@ export const useAttributionInitialization = () => {
         subscriptionRef.current = null;
       }
     };
-  }, [_hasHydrated, attributionStore]);
+  }, [_hasHydrated, _referralHasHydrated, attributionStore]);
 };

store/useReferralStore.ts

@@ -8,7 +8,9 @@ import mmkvStorage from '@/lib/mmvkStorage';
 
 interface ReferralState {
   referralCode: string | null;
+  _hasHydrated: boolean;
   setReferralCode: (code: string | null) => void;
+  setHasHydrated: (state: boolean) => void;
   clearReferralCode: () => void;
   detectAndSaveReferralCode: () => string | null;
   getReferralCodeForSignup: () => string | null;
@@ -21,6 +23,7 @@ export const useReferralStore = create<ReferralState>()(
   persist(
     (set, get) => ({
       referralCode: null,
+      _hasHydrated: false,
 
       setReferralCode: (code: string | null) => {
         const trimmedCode = code && code.trim() ? code.trim() : null;
@@ -30,6 +33,10 @@ export const useReferralStore = create<ReferralState>()(
         }
       },
 
+      setHasHydrated: (state: boolean) => {
+        set({ _hasHydrated: state });
+      },
+
       clearReferralCode: () => {
         set({ referralCode: null });
         console.warn('Referral code cleared');
@@ -95,6 +102,9 @@ export const useReferralStore = create<ReferralState>()(
     {
       name: USER.referralStorageKey,
       storage: createJSONStorage(() => mmkvStorage(USER.referralStorageKey)),
+      onRehydrateStorage: () => state => {
+        state?.setHasHydrated(true);
+      },
     },
   ),
 );

store/useSignupFlowStore.ts

@@ -111,7 +111,14 @@ export const useSignupFlowStore = create<SignupFlowState & SignupFlowActions>()(
       setRateLimitError: rateLimitError => set({ rateLimitError }),
       setLastOtpSentAt: lastOtpSentAt => set({ lastOtpSentAt }),
 
-      reset: () => set({ ...initialState, _hasHydrated: true }),
+      reset: () =>
+        set(state => ({
+          ...initialState,
+          _hasHydrated: true,
+          // Preserve referralCode captured at root level (attribution hook)
+          // This prevents accidental loss during flow resets
+          referralCode: state.referralCode || initialState.referralCode,
+        })),
     }),
     {
       name: `${USER.storageKey}_signup_flow`,