Ref T9519. When acquiring leases on resources:

• Only consider resources created by authorized blueprints.
• Only consider authorized blueprints when creating new resources.
• Fail with a tailored error if no blueprints are allowed.
• Fail with a tailored error if missing authorizations are causing acquisition failure.

One somewhat-substantial issue with this is that it's pretty hard to figure out from the Harbormaster side. Specifically, the Build step UI does not show field value anywhere, so the presence of unapproved blueprints is not communicated. This is much more clear in Drydock. I'll plan to address this in future changes to Harbormaster, since there are other related/similar issues anyway.