Raise a machine in use adopted: keep its firewall, load no dropping table, guard the mesh's own ports, and take only the mesh's own modules (hq ADR 0100)

cmd/mesh-bootstrap/main.go

@@ -135,6 +135,11 @@ const usage = `mesh-bootstrap — make a bare machine into a mesh
   --overlay-range    the private network's range (default 10.42.0.0/16); refused
                      if it overlaps an interface or route the machine already has
 
+  --adopted   raise a machine in use as an adopted node: what it runs and its
+              firewall stay as they are, the foundation's filter is not loaded and
+              the mesh guards its own ports instead, and each module is taken on it
+              one at a time. Without it, a machine in use is refused
+
 The installer carries a builder, not a control plane. What raises a mesh is therefore
 the same thing that will maintain it, and the control plane a mesh ends up running is
 one it built itself, from a repository and a commit it can name and build again.
@@ -312,6 +317,8 @@ func newFlagSet(opts *bootstrap.Options, jsonOut *bool) *flag.FlagSet {
 	} {
 		set.IntVar(p.into, p.name, *p.into, "the machine's port for "+p.what)
 	}
+	set.BoolVar(&opts.Adopted, "adopted", false,
+		"raise this machine adopted: keep what it runs and its firewall until each module is taken")
 	set.StringVar(&opts.OverlayRange, "overlay-range", opts.OverlayRange,
 		"the private network's address range; must not overlap a tunnel the machine already runs")
 	if opts.Answers == nil {