Add contract-product-arrange-qty API and form UI with green available qty,
red plan qty over-hint, and click-through dialog for usage and plan list.
Co-authored-by: Cursor <cursoragent@cursor.com>
Validate arranged+this plan qty against fixed contract product quantities on
transport arrange; return post-success remaining/framework cumulative reminders.
Co-authored-by: Cursor <cursoragent@cursor.com>