Hardens async assertions in the task detail modal's pause/unpause action tests, improving test reliability for that interaction flow.
Fusion-Task-Id: FN-3600
- Replace the monolithic TaskDetailModal test file with focused suites by behavior area
- Add shared TaskDetailModal test helpers to reduce duplication across suites
- Keep existing coverage while improving test isolation and maintainability
- Remove the legacy combined TaskDetailModal.test.tsx file
Fusion-Task-Id: FN-3591