Create ticket (admin)

Create a ticket from the system-admin flow.

Mirrors the user create endpoint but allows admin-only categories (integracoes) and an internal priority, and always validates assigned_to.

The ticket carries the acting admin's HOME company — never the one they may be impersonating. user["idcompany"] is ambient (see auth.home_company): an admin who switched into a tenant and then opened the system-admin panel would otherwise file this internal ticket INSIDE that tenant, where the tenant read path (db.tickets.list_tickets_by_company, which filters on idcompany alone) makes it readable by their users, and the attachment prefix below drops the files into that tenant's MultiDrive.