classes.ts: class/session CRUD (classes.manage; delete refused once
sessions/signups exist, archive instead), member signUpForClass /
cancelMySignup as validated service-client writes enforcing eligibility,
capacity vs waitlist, de-dupe and earliest-waitlist promotion on cancel,
listUpcomingSessions (service-client counts so members see spots-left
without seeing who signed up), instructor markAttendance and
completeSession. completeSession awards a class's certification via the
normal grantCertification path, so it only issues when the acting
instructor also holds certifications.grant; otherwise completion still
succeeds and reports certificatesSkipped. classes-guard mirrors the
forms/certifications guards. Barrel + API_REFERENCE updated.
Moheeb Zara
2732269d5f