- Consolidate steeringComments and comments into unified comments field using TaskComment type
- Remove SteeringComment type, migrate all comments to TaskComment format
- Update addComment to delegate to addTaskComment with auto-refinement for done tasks
- Merge legacy steeringComments data into comments during database migration
- Update dashboard API endpoint from /steer to /comments
- Update executor to use unified comments field for real-time injection
- Update PR comment handler to use addTaskComment method