Previous behavior:
Used billingSubscription.updatedAt (when the subscription record was
last modified)
Problem: updatedAt changes for ANY update, not just status changes,
making it unreliable for tracking when payment problems started
Current behavior:
Uses currentPeriodStart when subscription status is Unpaid or Canceled
Why it works: WORKSPACE_INACTIVE_DAYS_BEFORE_SOFT_DELETION is shorter
than the minimum billing interval (1 month). Then if a workspace is
unpaid for the entire current billing period, it will always exceed the
deletion threshold before the next period starts
Ideal fix:
Track workspace.suspendedAt explicitly, giving you the exact timestamp
of when payment problems began, regardless of billing periods.
