Ask again for a folder that moved, and carry entries left while a disk was away (hq ADR 0325)

The engine names the filesystem a waiting folder is on; a warrant is recorded for that filesystem, and a
folder on another is asked about again and not taken there meanwhile. Entries the engine could not take
out while their disk was away, stated before a send, do not hold that delivery's gate. mesh-host pinned
to d2d9fbbd.

internal/inventory/identities_test.go

@@ -96,6 +96,18 @@ func TestAFolderIsTakenOnceUnderAWarrant(t *testing.T) {
 	if !has || got.Ask != "c01" || got.By != "the operator" {
 		t.Fatalf("the taken folder reads %+v (%v): the first take, by its clean path", got, has)
 	}
+	// The folder moved to another filesystem and the operator was asked again: the new take replaces the old.
+	if err := inv.RecordTaken(ctx, "ace", TakenFolder{Path: "/storage/media/movies", By: "the operator", Ask: "c03",
+		Warrant: "c03", Placed: "fs-0000000000ff"}); err != nil {
+		t.Fatal(err)
+	}
+	kept, err = inv.KeptFolders(ctx, "ace")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := kept["/storage/media/movies"]; got.Ask != "c03" || got.Placed != "fs-0000000000ff" {
+		t.Fatalf("after a take on another filesystem the folder reads %+v", got)
+	}
 }
 
 // novox/hq issue 575: a module registered without the access movies, whose newest build on its branch declares it —