An address is read from the node's settings where it is used, never recorded with a port

Three readers did not follow a moved foundation port (novox/hq 04-ISSUES/102),
and each took the control-node down in its own way: the control plane's own
store and broker connections, sealed at genesis with the port inside; and every
build the mesh ever recorded, kept as `<registry>:<port>/<module>/<artifact>@…`.

The control plane cannot open its own sealed connections to move a port, and it
cannot bind the store as a consumer would — a binding mints a credential. So its
settings get a third twin, `NAME_PORT`, read on top of the sealed value by the
store, the broker, the management API and the bus connection, and filled into
its container by a placeholder that names a seat, `${seat:mesh-store:5432}`,
from the node's given or mesh-assigned ports — never the manifest's number, and
empty when the mesh has nothing to add, so what genesis wrote stands. A value
that is still a placeholder is nothing said, aloud: the manifest naming it lands
in the next commit, once every control plane that composes it knows it.

A build is now recorded by digest and path — `artifact-store://<module>/<artifact>@…`
— and the store's address is composed in where a reference is used: the
declaration, the trust file, the bases a build is handed, a replay to the
catalogue. Over the network as `<node>.internal:<port>`; on the store's own node
before any network exists — every genesis push before its "network" step — by
loopback. A reference recorded before this, with an address, is re-routed the
same way when the mesh built it. The trust file and every provider's address
come from one derivation: the node's given port, over the mesh's assignment,
over the manifest's number.

novox/hq 04-ISSUES/102

internal/broker/broker.go

@@ -40,8 +40,12 @@ type Broker struct {
 var ErrNotConfigured = errors.New("this control plane has not been told about its broker")
 
 // FromEnvironment reads the two settings, if they are there.
+//
+// The address's port follows MESH_BROKER_ADDRESS_PORT when the node's settings moved the bus
+// (novox/hq 04-ISSUES/102): the address genesis wrote is a public name and the port genesis
+// chose, and only the port is the node's to move.
 func FromEnvironment() (Broker, error) {
-	address, err := envfile.Value(AddressVar)
+	address, err := envfile.Placed(AddressVar)
 	if err != nil {
 		return Broker{}, err
 	}