Filtered Submission Limit (Count only submissions matching a condition)

Current behavior: "Limit number of submissions" counts all submissions regardless of their content. Once the limit is reached, the form closes.

Problem: I use the form as an event sign-up (quiz night). Participants can update their status to "Not coming," but those entries still count toward the submission limit. This means the event appears full even when spots have freed up.

Proposed behavior: Allow an optional filter on the submission limit, so only submissions matching a condition count toward the limit.

Example configuration:

• Limit: 30 submissions

• Count only where: status == "Going"

A participant who changes their status to "Not coming" would no longer count, freeing up their spot automatically.

Use case: A coffee shop runs weekly quiz nights for 30 people. Sign-ups come through the form. When someone cancels (status → "Not coming"), their spot should reopen without manual intervention. Currently, the organizer must manually increase the limit or reopen the form.