Rename the mesh's seats to mesh-*, keeping their interfaces

novox/hq ADR 0118: the prefix is the reservation rule, so a module
declaring any mesh-* name is refused and there is no reserved-names list to
drift. Ten seats renamed in the table, the manifests that claim them, the
controller's own shipped manifests, and the tests.

Not the migration 0118 expected: a holding is derived at resolution from
manifests and never stored, so nothing recorded points at an old name. A
kept rename table tells a manifest written against one what it became —
kept rather than retired, because a module lives in its own repository and
may be registered long after the catalogue stopped using it.

**A seat is not the interface it delivers.** The git seat became mesh-git
and the git provision did not; likewise the package registry. A blanket
replace renamed both, and the failure read "the package registry is served
on <nil>", which does not say "you renamed an interface". A test now pins
every seat against what it delivers, and that neither name is also the
other.

internal/catalogue/resolver_manifests_test.go

@@ -170,7 +170,7 @@ func TestTwoThingsDecidingWhatAMachineAsksAreRefused(t *testing.T) {
 	if err == nil {
 		t.Fatal("resolv-conf and resolved-split-dns were both assigned to one machine")
 	}
-	if !strings.Contains(err.Error(), "the-resolver-configuration") {
+	if !strings.Contains(err.Error(), "mesh-resolver-configuration") {
 		t.Fatalf("the refusal does not say what was claimed: %v", err)
 	}
 }