allow creating offers with blinded paths when you have public channels

https://blog.blockstream.com/core-lightning-v24-08-steel-backed-up-channels/ says "The offers plugin now automatically adds a blinded path from a peer **when there are no public channels available**, enabling unannounced nodes to generate and manage offers securely without exposing their channels publicly."

Not sure why you don't have an option to create blinded paths if you **do** have public channels?

Either way, there is no logging (either in the log file (I have `log-level=debug:plugin-offers` set by the way) or in response to `lightning-cli offer` or `lightning-cli listoffers`) indicating that a blinded path is used or not used, and I think that should definitely be done. Currently I have to use `lightning-cli decode lno1xxxxxx` in order to check. Lots of people think BOLT12 offers are private and use blinded paths, but it seems very easy to not do so in CLN with the current behavior.