Feature/#82 add joinedat field to user

[rozita-hasani]

#82 Add joinedat field to user

Description

Add joinedat field to user

Changes

• Add joinedAt field and start date picker to user create
• Add joinedAt field and start date picker to user list
• Add joinedAt field and start date picker to user update

Checklist

• Code adheres to the project’s back-end guidelines.
• Unit tests cover new functionality.
• Integration tests are added or updated.
• Exception handling is implemented consistently.
• Logging is added for critical operations.
• Database migrations (if applicable) are included and tested.
• API documentation is updated if necessary.
• Changes are reviewed for potential performance impacts.
• Security vulnerabilities are assessed and mitigated.
• Dependencies are updated or verified as compatible.
• Code is reviewed for readability and maintainability.
• Environment configurations (if any) are documented.
• Endpoints are tested for expected behavior.