Refactor SessionManager into SessionTracker

[bhouston]

Refactor SessionManager into SessionTracker

Description

Currently, the agent package has both a SessionManager and a SessionTracker class that appear to be tracking the same thing. This refactor will consolidate these two classes, merging the functionality of SessionManager into SessionTracker.

Why

• Reduces code duplication
• Simplifies the codebase
• Makes the session management more consistent
• Eliminates confusion about which class to use for which purpose

Implementation Details

1. Analyze both classes to understand their responsibilities
2. Merge the functionality of SessionManager into SessionTracker
3. Update all imports and references to SessionManager
4. Remove the SessionManager class
5. Update any tests that rely on SessionManager

Acceptance Criteria

• All functionality remains the same
• All tests pass
• Build completes successfully
• No references to SessionManager remain in the codebase
• SessionTracker handles all responsibilities previously managed by both classes

[bhouston]

done.