- Rename npm packages from @kb/* to @hai/* and update all workspace references
- Rename CLI binary from kb to hai and config directory from .kb to .hai
- Update dashboard UI branding, titles, and references from kb to hai
- Update all test files, CI workflows, and documentation to reflect new naming
- Run comprehensive grep verification to ensure no stale kb references remain
- Set task status to 'failed' on execution failure in engine executor
- Add failed indicator styling on TaskCard component
- Add POST /tasks/:id/retry API endpoint and client function
- Add retry button in TaskDetailModal for failed tasks
- Add tests for failed indicator, retry endpoint, and modal behavior
