Add pending_approval agent status, permissions jsonb column, and AgentPermissions
type with canCreateAgents flag. Add approval_comments table and ApprovalComment
type. Extend approval statuses with revision_requested. Add validators for
permission updates, approval revision requests, resubmission, and approval
comments. Add requireBoardApprovalForNewAgents to company update schema.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>