[Feature] Round Robin: Add optional max-hosts auto-assignment (multi-host RR)

[linear[bot]]

Description:

Customers are requesting an enhancement to Round Robin that allows assigning more than one host when multiple hosts are available at the selected time.

Current behavior:

• Round Robin: always assigns one host.
• Collective: requires all hosts to be available.

Requested behavior:

A hybrid mode:

• Use union availability (same as current RR).
• When confirming the booking, auto-assign up to a configurable maximum number of hosts.
• Minimum remains 1 (default RR behavior).

Example:

• Event type has 5 interviewers added.
• Candidate selects a time where 4 are available.
• If maxHosts = 3 → assign 3 automatically.

Implementation notes:

• Availability loading stays unchanged (RR union logic).
• Logic change is only at booking confirmation: determine available hosts, then assign up to maxHosts.
• Add an event-type-level config: maxRoundRobinHosts (default = 1).

Acceptance Criteria:

• Event types support configuring a maxRoundRobinHosts value.
• RR availability behavior remains unchanged.
• When booking:
  • System detects available hosts.
  • Assigns up to the configured maximum.
  • Always assigns at least 1 host.
• UI/API reflect the new setting.
• Backwards compatible with existing RR configurations.

[linear[bot]]

CAL-6840

[Zopsss]

@pedroccastro can I try working on this?

[pedroccastro]

@pedroccastro can I try working on this?

Hey @Zopsss! Thanks for your interest in contributing, really appreciate it! I’m actually already working on this one and just opened a draft PR today, it should be ready for review soon. Feel free to pick up another unassigned issue in the meantime. I’d love to see your contributions! 🙌