feat(auth): migrate to Better Auth + OAuth 2.1 for MCP

apps/expo/app/(app)/ai-chat.tsx

@@ -20,9 +20,9 @@ import { LocationContext } from 'expo-app/features/ai/components/LocationContext
 import { CustomChatTransport } from 'expo-app/features/ai/lib/CustomChatTransport';
 import { getLocalModel, initLocalModel } from 'expo-app/features/ai/lib/localModelManager';
 import { createLocalTools } from 'expo-app/features/ai/lib/tools';
-import { tokenAtom } from 'expo-app/features/auth/atoms/authAtoms';
 import { useActiveLocation } from 'expo-app/features/weather/hooks';
 import type { WeatherLocation } from 'expo-app/features/weather/types';
+import { authClient } from 'expo-app/lib/auth-client';
 import { useColorScheme } from 'expo-app/lib/hooks/useColorScheme';
 import { useTranslation } from 'expo-app/lib/hooks/useTranslation';
 import { getContextualGreeting, getContextualSuggestions } from 'expo-app/utils/chatContextHelpers';
@@ -90,7 +90,8 @@ export default function AIChat() {
   const locationRef = React.useRef(context.location);
   locationRef.current = context.location;
 
-  const token = useAtomValue(tokenAtom);
+  const { data: _authSession } = authClient.useSession();
+  const token = _authSession?.session?.token ?? null;
   const [input, setInput] = React.useState('');
   const [lastUserMessage, setLastUserMessage] = React.useState('');
   const [previousMessages, setPreviousMessages] = React.useState<UIMessage[]>([]);

apps/expo/app/(app)/feed/[id].tsx

@@ -8,7 +8,7 @@ import { ActivityIndicator, View } from 'react-native';
 
 export default function PostDetailRoute() {
   const { id } = useLocalSearchParams<{ id: string }>();
-  const currentUserId = userStore.id.peek() as number | undefined;
+  const currentUserId = userStore.id.peek() as string | undefined;
 
   const { data: post, isLoading } = useQuery({
     queryKey: ['feed', Number(id)],

apps/expo/app/auth/(login)/reset-password.tsx

@@ -136,7 +136,7 @@ export default function ResetPasswordScreen() {
         setIsLoading(true);
 
         // Call the API to reset the password
-        await resetPassword(params.email, { code: params.code, newPassword: value.password });
+        await resetPassword(params.email, { token: params.code, newPassword: value.password });
 
         // Show success message and navigate to login
         Alert.alert(t('common.success'), t('auth.resetPasswordSuccess'), [

apps/expo/features/auth/atoms/authAtoms.ts

@@ -1,39 +1,5 @@
-import Storage from 'expo-sqlite/kv-store';
 import { atom } from 'jotai';
-import { atomWithStorage } from 'jotai/utils';
 
-// User type definition
-export type User = {
-  id: number;
-  email: string;
-  firstName?: string;
-  lastName?: string;
-  emailVerified: boolean;
-};
-
-// Token storage atom
-export const tokenAtom = atomWithStorage<string | null>('access_token', null, {
-  getItem: (key) => Storage.getItemSync(key),
-  setItem: (key, value) => {
-    if (value === null) return Storage.removeItemSync(key);
-    return Storage.setItemSync(key, value);
-  },
-  removeItem: (key) => Storage.removeItemSync(key),
-});
-
-export const refreshTokenAtom = atomWithStorage<string | null>('refresh_token', null, {
-  getItem: (key) => Storage.getItemSync(key),
-  setItem: (key, value) => {
-    if (value === null) return Storage.removeItemSync(key);
-    return Storage.setItemSync(key, value);
-  },
-  removeItem: (key) => Storage.removeItemSync(key),
-});
-
-// Loading state atom
 export const isLoadingAtom = atom(false);
-
 export const redirectToAtom = atom<string>('/');
-
-// Re-authentication state
 export const needsReauthAtom = atom(false);