2026/11/02 Fixed an issue where the longest and shortest paths could not be calculated in a flow that includes a rework process

In flows containing steps that exist only beyond back edges (such as rework steps), the longest and shortest paths displayed as "Cannot be calculated" and were not shown.
This has been fixed so that the paths are calculated and displayed by excluding steps that exist only within back-edge routes.
The Effort for excluded steps can still be calculated even without being included.