NextAuth Session Not Persisting After Refresh

1. No session adapter configured (defaults to JWT, not persisted in database)
2. JWT maxAge set too low or 0, expiring immediately
3. Session cookie sameSite: 'Lax' blocking cross-site persistence
4. Database session table not created or inaccessible
5. Cookie secure flag preventing HTTP localhost testing

Add session adapter: For persistent sessions, use database adapter:
adapter: PrismaAdapter(prisma),
session: { strategy: 'database' }

Or extend JWT: If using JWT, increase maxAge and set callbacks:
jwt: { maxAge: 30 * 24 * 60 * 60 }, // 30 days

Check cookie settings: Ensure sameSite: 'Lax' or 'None', secure only in production (HTTPS).

Test with /api/auth/session: Call this route to verify session is persisted. Should return user object after login.