C-01: Use func.count() for invitation cap instead of loading all rows
C-02: Remove unused display_calendar_id from EventInvitationResponse
F-01: Add field allowlist for invited editors (blocks is_starred,
recurrence_rule, calendar_id mutations)
W-02: Memoize existingInviteeIds Set in EventDetailPanel
W-03: Block per-occurrence overrides on declined/pending invitations
S-01: Make can_modify non-optional in EventInvitation TypeScript type
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>