Get dates for the most recent plenary week (Monday-Thursday).
If a specific week start date is provided, uses that week.
Otherwise calculates the most recent Monday.
Parameters
OptionalweekStart: string
Optional Monday date (YYYY-MM-DD) to use as start of plenary week
Returns string[]
Array of date strings for the plenary week (Mon-Thu)
Get dates for the most recent plenary week (Monday-Thursday). If a specific week start date is provided, uses that week. Otherwise calculates the most recent Monday.