SOP support-api: add ticket CRUD (close/status/notify) + private stakeholder comments

Sub-item of EVO-52. Mars support-api needs: full ticket status transitions (incl. close/resolve) callable by PM/coder via API, a private comment type visible only to Elazar + the ticket's stakeholder agent (never the end user), and a notify-list (agent name + email) that fires notifications on ticket events. No direct DB writes or chrome-mcp driving tickets — API only.