feat(story-1.5): add React frontend with auth pages and dark theme

web/src/stores/authStore.ts

@@ -0,0 +1,34 @@
+import { create } from 'zustand';
+import { persist } from 'zustand/middleware';
+
+interface User {
+    id: string;
+    email: string;
+    is_admin: boolean;
+}
+
+interface AuthState {
+    user: User | null;
+    isAuthenticated: boolean;
+    isLoading: boolean;
+    setUser: (user: User | null) => void;
+    setLoading: (loading: boolean) => void;
+    logout: () => void;
+}
+
+export const useAuthStore = create<AuthState>()(
+    persist(
+        (set) => ({
+            user: null,
+            isAuthenticated: false,
+            isLoading: true,
+            setUser: (user) => set({ user, isAuthenticated: !!user, isLoading: false }),
+            setLoading: (isLoading) => set({ isLoading }),
+            logout: () => set({ user: null, isAuthenticated: false }),
+        }),
+        {
+            name: 'auth-storage',
+            partialize: (state) => ({ user: state.user, isAuthenticated: state.isAuthenticated }),
+        }
+    )
+);