Phase 0: Fix token race condition causing logout after login

- Updated getAuthToken/getRefreshToken to read from Zustand store first (faster, no parsing delay)
- Added token existence check before making API calls in AppLayout
- Added retry mechanism with 100ms delay to wait for Zustand persist to write token
- Made 403 error handler smarter - only logout if token actually exists (prevents false logouts)
- Fixes issue where user gets logged out immediately after successful login

frontend/src/services/api.ts

@@ -78,9 +78,16 @@ function getActiveSectorId(): number | null {
   }
 }
 
-// Get auth token from store
+// Get auth token from store - try Zustand store first, then localStorage as fallback
 const getAuthToken = (): string | null => {
   try {
+    // First try to get from Zustand store directly (faster, no parsing)
+    const authState = useAuthStore.getState();
+    if (authState?.token) {
+      return authState.token;
+    }
+    
+    // Fallback to localStorage (for cases where store hasn't initialized yet)
     const authStorage = localStorage.getItem('auth-storage');
     if (authStorage) {
       const parsed = JSON.parse(authStorage);
@@ -92,9 +99,16 @@ const getAuthToken = (): string | null => {
   return null;
 };
 
-// Get refresh token from store
+// Get refresh token from store - try Zustand store first, then localStorage as fallback
 const getRefreshToken = (): string | null => {
   try {
+    // First try to get from Zustand store directly (faster, no parsing)
+    const authState = useAuthStore.getState();
+    if (authState?.refreshToken) {
+      return authState.refreshToken;
+    }
+    
+    // Fallback to localStorage (for cases where store hasn't initialized yet)
     const authStorage = localStorage.getItem('auth-storage');
     if (authStorage) {
       const parsed = JSON.parse(authStorage);
@@ -148,9 +162,14 @@ export async function fetchAPI(endpoint: string, options?: RequestInit & { timeo
         if (errorData?.detail?.includes('Authentication credentials') || 
             errorData?.message?.includes('Authentication credentials') ||
             errorData?.error?.includes('Authentication credentials')) {
-          // Token is invalid - clear auth state and force re-login
-          const { logout } = useAuthStore.getState();
-          logout();
+          // Only logout if we actually have a token stored (means it's invalid)
+          // If no token, it might be a race condition after login - don't logout
+          const authState = useAuthStore.getState();
+          if (authState?.token || authState?.isAuthenticated) {
+            // Token exists but is invalid - clear auth state and force re-login
+            const { logout } = useAuthStore.getState();
+            logout();
+          }
           // Don't throw here - let the error handling below show the error
         }
       } catch (e) {