Implement session cleanup for expired sessions

[davedumto]

Problem

No cleanup mechanism for expired sessions, leading to:

• Accumulation of expired session data
• Memory leaks from old session data
• Database bloat from unused sessions
• Performance degradation over time

Impact

• Memory usage grows over time
• Database performance degrades
• Potential security risks from old session data
• Poor system performance

Solution

Implement automated session cleanup:

• Scheduled cleanup of expired sessions
• Memory cleanup for session data
• Database cleanup for old session records
• Session lifecycle management

Implementation

• Add scheduled session cleanup job
• Implement session expiration tracking
• Add cleanup for Redis session data
• Add cleanup for database session records

Acceptance Criteria

• Automated session cleanup job
• Cleanup of expired Redis sessions
• Cleanup of expired database sessions
• Session lifecycle monitoring
• Memory usage optimization