Implement Event, Session, and Team Management UI

[KSiig]

Currently, new sessions are created from configOptions, and new events are managed by cloning an existing event. To streamline the workflow and provide better usability, implement a dedicated management menu for:

• Events
• Sessions
• Teams

This menu should allow users to:

• Create, edit, and delete events
• Create, edit, and delete sessions
• Create, edit, and delete teams

This will greatly improve the flexibility and maintainability of the event/session/team workflow in StintFlow.