Genesis raises the package registry before it builds the base

The base (mesh-tools) resolves the SDK by version from the mesh's package
registry rather than cloning it from a git URL (hq ADR 0076, issue 053), so the
registry has to answer and the SDK has to be in it before the base build runs.

New steps, before base: seed gitea's database in the substrate store, raise
gitea's server on it, create the admin/org/team and the builder's account, seal
the builder its registry credential, and publish the SDK on a public base. gitea
is adopted as an ordinary module after the base, so its provisioner image can be
built. A minimal Go gitea admin client stands in until that module exists.

Claude-Session: https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx

cmd/mesh-bootstrap/main.go

@@ -117,6 +117,8 @@ const usage = `mesh-bootstrap — make a bare machine into a mesh
   --catalog-source   the catalogue REPOSITORY, for building its modules;
                      --catalog is the checkout that says what they are
   --catalog-ref      what of it to build (default main)
+  --sdk-source       the repository the shared library is built from
+  --sdk-ref          what of it to build (default main)
   --private-network  which private network to run (wireguard)
   --endpoint         host:port other machines dial for it; derived from the
                      broker address when unsaid
@@ -248,6 +250,10 @@ func newFlagSet(opts *bootstrap.Options, jsonOut *bool) *flag.FlagSet {
 		"the catalogue REPOSITORY, for building its modules — --catalog is the checkout that says what they are")
 	set.StringVar(&opts.CatalogSource.Ref, "catalog-ref", opts.CatalogSource.Ref,
 		"what of it to build (default main)")
+	set.StringVar(&opts.SDKSource.Repository, "sdk-source", opts.SDKSource.Repository,
+		"the repository the shared library is built from, published before the base resolves it")
+	set.StringVar(&opts.SDKSource.Ref, "sdk-ref", opts.SDKSource.Ref,
+		"what of it to build (default main)")
 	set.StringVar(&opts.Site, "site", "main", "where this machine sits, for the private network")
 	if opts.Answers == nil {
 		opts.Answers = map[string]string{}