Refactors authentication logic into AuthContext and removes useAuth hook. Replit-Commit-Author: Agent Replit-Commit-Session-Id: 556aa286-edd2-4cea-8583-f4fc3cfd119b
Refactors authentication logic into AuthContext and removes useAuth hook. Replit-Commit-Author: Agent Replit-Commit-Session-Id: 556aa286-edd2-4cea-8583-f4fc3cfd119b