Improve agent metadata tracking with completion state and changes detection #9286
Description
Currently agent metadata updates don't track whether a session is complete or if any changes were made during the session. This makes it difficult to analyze agent usage patterns and effectiveness.
Problem:
- Agent metadata lacks completion state information
- No tracking of whether sessions actually made changes to the codebase
- Metadata collection is not modular/reusable
Solution needed:
- Add completion state tracking to agent metadata
- Detect and include whether changes were made (via git diff)
- Refactor metadata collection into modular helpers
- Maintain backward compatibility with existing metadata API
This will enable better analytics and understanding of agent session outcomes.