Customer portal: let users view & release their own activated devices

For license-key products with a device activation limit, when customers reinstall their OS, switch devices, or wipe a disk, the old device still occupies an activation slot — so activating a new device shows "Device limit reached."

Customers currently cannot free slots themselves — there's no entry in the customer portal to view all activated devices under a license and revoke them. They can only contact the merchant for manual deletion each time.

Request:

• Add a license-management view in the customer portal where the customer can see all activated devices under their license.
• Let them release / revoke a device slot themselves.

Impact: Recurring issue that currently requires manual backend processing by the merchant on every device change.

Reported by merchant: Mole (bus_0Ndre3BwB57i3ShiBfln7)