Well, the Terms of Use for STLINK-MINIE can be found on the product website, tab Documentation, which, among other things, do not permit such use:
The Evaluation Board shall not be, in any case, directly or indirectly assembled as a part in any production of Yours as it is solely developed to serve evaluation an d testing purposes and has no direct function and is not a finished product.
If the Evaluation Board is incorporated in an evaluation system, the evaluation system may be used by You solely for Your evaluation and testing purposes. Such evaluation system may not be offered for sale or lease or sold, leased or otherwise distributed for commercial purposes and must be accompanied by a conspicuous notice as follows: “This device is not, and may not be, offered for sale or lease, or sold or leased or otherwise distributed for commercial purposes”.
Only for the STLINK-V3MODS is no such restriction to be found so far, no licence is required and you can solder it onto your board.
Hope that helps?
Regards
/Peter