Replace localStorage session data with distributed session management

[davedumto]

Problem

Session data uses localStorage which is not distributed:

localStorage.getItem(this.SESSION_KEY)

This causes issues with:

• Multiple server instances
• Load balancer scenarios
• Session persistence across deployments
• Scalability for 200+ users

Impact

• Sessions lost when hitting different server instances
• Poor user experience with session inconsistencies
• Cannot scale horizontally
• Session data not shared across instances

Solution

Implement distributed session management:

• Use Redis for session storage
• Implement session cleanup for expired sessions
• Add session validation and security
• Ensure session persistence across instances

Files to modify

• src/lib/session.ts

Acceptance Criteria

• Replace localStorage with Redis session storage
• Implement session cleanup for expired sessions
• Add session validation and security
• Test session persistence across instances
• Verify session management with 200+ users