Add a warning with confirmation when switching to Point Based Levels

[sudo-may]

When enabling Point-Based Levels management, administrators must be aware that they assume full responsibility for explicitly defining each level's point ranges. The system will display a clear warning about this responsibility during the switch.
As you add new skills and increase the total available points, it's crucial to review and adjust level thresholds accordingly. Without proper maintenance, users may unexpectedly reach the maximum level prematurely if the level ranges aren't updated to reflect the expanded point pool. Could also recommend regularly reviewing and adjusting level thresholds whenever new skills are introduced.