[Feature]: No warnings when Work Center Calendars are not calculated

Describe the issue

Work center calendars are usually calculated on a yearly basis or even less. If that is forgotten there are no warnings at all.
In the planning worksheet it can be seen after calculating regenerative plan that the starting date is much earlier than the due date, which is usually not noticed. There should be a warning so that it is noticed.

Expected behavior

A warning in the planning worksheet.

Steps to reproduce

Steps in Cronus, that has calendars calculated for 2027 and 2028 currently.

1. Create a sales order with shipment date in 2030 and item 1001.
2. In Planning Worksheet use Calculate Regenerative Plan for Item 1001 and set ending date after the shipment date on the order.
3. Notice the big difference between due date and starting date, and that there are no warnings.

Additional context

This is a common problem that usually goes unnoticed until it starts generating real problems. It usually requires help since the user doesn't understand why the results are so strange. Often it costs money also because components are ordered earlier than needed.

It should only warn if it's the last capacity for the work/machine centers that has been used. (Since there might be missing capacities for an indvidiual work center)

The bad planning might be more difficult to notice than in the example. In more complex cases the ending date might be correct, and just the starting date is unreasonably early.

This should not be an error, since there can be good reasons for capacity stopping at some point.

I will provide a fix for a bug

• I will provide a fix for a bug

Start in the Planning Worksheet flow around Calculate Regenerative Plan, then trace how Work Center Calendars and the final capacity are evaluated. Reproduce the Cronus scenario with item 1001 and a 2030 shipment date. Done means the Planning Worksheet warns when the last capacity is missing, while still allowing intentional capacity limits and avoiding an error.