feat: Expo scaffold + auth screens + core screens (#39-#46, #48)

stores/auth.store.ts

@@ -0,0 +1,64 @@
+import { create } from 'zustand';
+import * as SecureStore from 'expo-secure-store';
+import { STORAGE_KEYS } from '../constants';
+
+interface User {
+  id: number;
+  name: string;
+  username: string;
+  email: string;
+  role: string;
+  tenant_slug: string;
+}
+
+interface AuthState {
+  token: string | null;
+  user: User | null;
+  tenantSlug: string | null;
+  isLoading: boolean;
+  isAuthenticated: boolean;
+
+  setAuth: (token: string, user: User) => Promise<void>;
+  setTenantSlug: (slug: string) => void;
+  logout: () => Promise<void>;
+  loadFromStorage: () => Promise<void>;
+}
+
+export const useAuthStore = create<AuthState>((set) => ({
+  token: null,
+  user: null,
+  tenantSlug: null,
+  isLoading: true,
+  isAuthenticated: false,
+
+  setAuth: async (token, user) => {
+    await SecureStore.setItemAsync(STORAGE_KEYS.TOKEN, token);
+    await SecureStore.setItemAsync(STORAGE_KEYS.USER, JSON.stringify(user));
+    set({ token, user, isAuthenticated: true, tenantSlug: user.tenant_slug });
+  },
+
+  setTenantSlug: (slug) => {
+    set({ tenantSlug: slug });
+  },
+
+  logout: async () => {
+    await SecureStore.deleteItemAsync(STORAGE_KEYS.TOKEN);
+    await SecureStore.deleteItemAsync(STORAGE_KEYS.USER);
+    set({ token: null, user: null, isAuthenticated: false });
+  },
+
+  loadFromStorage: async () => {
+    try {
+      const token = await SecureStore.getItemAsync(STORAGE_KEYS.TOKEN);
+      const userStr = await SecureStore.getItemAsync(STORAGE_KEYS.USER);
+      if (token && userStr) {
+        const user = JSON.parse(userStr) as User;
+        set({ token, user, isAuthenticated: true, tenantSlug: user.tenant_slug, isLoading: false });
+      } else {
+        set({ isLoading: false });
+      }
+    } catch {
+      set({ isLoading: false });
+    }
+  },
+}));