Timesheet Validation Alert: Potential duplicate entry for leave and actual work done on the same dayed

Introduce a system validation that detects when leave is recorded for a specific day and working hours are also captured for the same day.

Proposed behaviour:

• When submitting or approving a timesheet, the system should trigger an alert.

• The alert should notify the user of the potential duplication and request confirmation or correction before proceeding.

• Optionally, a warning can also display when downloading the monthly Timesheet Summary Report to highlight affected entries for review