Rename mesh-control -> mesh-controller, substrate -> foundation

One name per thing, per the HQ glossary: the module/container/image/binary/repo
becomes mesh-controller, the seat the-controller, and the store+broker pair the
foundation (embedded base bundles, default template and example lock renamed with
their go:embed directives). No behaviour change — a pure vocabulary rename.

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

examples/modules/modules_test.go

@@ -10,8 +10,8 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/novox/mesh-control/internal/catalogue"
-	"github.com/novox/mesh-control/internal/overlay"
+	"github.com/novox/mesh-controller/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/overlay"
 )
 
 // The examples are manifests, so the thing to check is that the catalogue accepts them.

examples/postgres-provisioner/where_test.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/novox/mesh-control/internal/catalogue"
+	"github.com/novox/mesh-controller/internal/catalogue"
 )
 
 // The password comes from a file, because that is how the mesh delivers one.