Players meeting a role's minimum rank and MOS can queue for mission roles before op time. Slot holders are recomputed statelessly from signup order plus current RSVP (first N committed signups hold the role); attendance writes diff holders around the write so RSVP changes auto-promote, with notifications and events. Adds mission-role-signups collection, roleSignups/missionTime libs, sign-up panel, role slots + rich-text descriptions (with RoleDescription renderer), orphan-pruning hook, migrations, tests, and AGENTS.md docs.
