Adds a check to ensure milestone names are unique within a project, blocking creation if the name is already used for an active or finished milestone. Improves error messaging for failed milestone creation.

Pull Request Checklist

• I have read and followed the contribution guidelines.
• My pull request targets the main branch of tmpo.
• I have tested these changes locally on my machine.

Description

This pull request adds a validation step to the milestone creation command to prevent duplicate milestone names, improving data integrity and user experience. Now, if a milestone name has already been used (either for an active or finished milestone), the command will display a clear error message and exit, guiding the user on how to proceed.

Milestone name validation:

• Added a check in cmd/milestones/start.go to ensure that a milestone name is not reused for the same project, whether the milestone is currently active or has been finished in the past. Displays specific error messages based on milestone status and prevents creation if a conflict is found.

Screenshots