feat: add Zustand stores and custom hooks

frontend-mobile/hooks/useAuth.ts

@@ -0,0 +1,19 @@
+import { useEffect } from 'react';
+import { useAuthStore } from '../store/authStore';
+
+export function useAuth() {
+  const { user, isLoading, isAuthenticated, login, logout, checkAuth } = useAuthStore();
+
+  useEffect(() => {
+    checkAuth();
+  }, []);
+
+  return {
+    user,
+    isLoading,
+    isAuthenticated,
+    login,
+    logout,
+    isAdmin: user?.is_admin ?? false,
+  };
+}

frontend-mobile/hooks/useDebounce.ts

@@ -0,0 +1,17 @@
+import { useState, useEffect } from 'react';
+
+export function useDebounce<T>(value: T, delay: number): T {
+  const [debouncedValue, setDebouncedValue] = useState<T>(value);
+
+  useEffect(() => {
+    const timer = setTimeout(() => {
+      setDebouncedValue(value);
+    }, delay);
+
+    return () => {
+      clearTimeout(timer);
+    };
+  }, [value, delay]);
+
+  return debouncedValue;
+}

frontend-mobile/store/authStore.ts

@@ -0,0 +1,38 @@
+import { create } from 'zustand';
+import { User } from '../types';
+import * as authService from '../services/auth';
+
+interface AuthState {
+  user: User | null;
+  isLoading: boolean;
+  isAuthenticated: boolean;
+  login: (username: string, password: string) => Promise<void>;
+  logout: () => Promise<void>;
+  checkAuth: () => Promise<void>;
+}
+
+export const useAuthStore = create<AuthState>((set) => ({
+  user: null,
+  isLoading: true,
+  isAuthenticated: false,
+
+  login: async (username: string, password: string) => {
+    const { user } = await authService.login(username, password);
+    set({ user, isAuthenticated: true });
+  },
+
+  logout: async () => {
+    await authService.logout();
+    set({ user: null, isAuthenticated: false });
+  },
+
+  checkAuth: async () => {
+    set({ isLoading: true });
+    const user = await authService.checkAuth() || await authService.getStoredUser();
+    set({ 
+      user, 
+      isAuthenticated: !!user, 
+      isLoading: false 
+    });
+  },
+}));

frontend-mobile/store/searchStore.ts

@@ -0,0 +1,27 @@
+import { create } from 'zustand';
+import { Medicine } from '../types';
+
+interface SearchState {
+  query: string;
+  results: Medicine[];
+  isLoading: boolean;
+  error: string | null;
+  setQuery: (query: string) => void;
+  setResults: (results: Medicine[]) => void;
+  setLoading: (loading: boolean) => void;
+  setError: (error: string | null) => void;
+  clearResults: () => void;
+}
+
+export const useSearchStore = create<SearchState>((set) => ({
+  query: '',
+  results: [],
+  isLoading: false,
+  error: null,
+
+  setQuery: (query) => set({ query }),
+  setResults: (results) => set({ results, isLoading: false }),
+  setLoading: (isLoading) => set({ isLoading }),
+  setError: (error) => set({ error, isLoading: false }),
+  clearResults: () => set({ results: [], query: '', error: null }),
+}));