Add written approval link to support ticket thread

Deal approval files don't surface in support tickets, leaving agents without verification during customer inquiries. This pins the approval link to the ticket so agents and customers see it quickly.

Overview

Support often lacks visible approval documentation when customers ask for verification, causing time-consuming handoffs with sales. This flow posts the deal's approval link directly on the ticket so agents and customers have proof at-hand, enabling faster replies and same-day resolution.