Remove authentication system

[Dustin-Reyes]

Remove all authentication-related code as it's not needed for the menu display template.

Tasks:

• Delete src/context/AuthContext.jsx
• Remove src/components/auth/ directory
• Remove AuthProvider from App.jsx
• Remove useAuth imports throughout codebase
• Update Header.jsx (remove user menu references)
• Clean up any auth-related utilities

Acceptance Criteria:

• No auth context or components exist
• App runs without auth dependencies
• No broken imports or references
• Header displays correctly without user menu

Sprint: 1 - Clean Up & Structure