The registry reserves 20000-20099 for Gitea and requires new blocks to come
from the 21500-21999 free pool, claimed only once a service is actually
listening. Also corrects the clone URL to fisher/my-cd-webhook.
Replaces the per-project deploy scripts and self-contained webhook
receivers with one manifest-driven implementation that lives outside the
application repositories and can be updated independently of them.
First targets: domaindingo test and prod on s5.
fisher