mesh-knowledge: ask changes in the review for a decision nothing would cite, so its acceptance never turns the module unhealthy (hq issue 504)

The whole-set rule cited ran only after acceptance: the review approved a
decision with no home and no record linking it, the rule then failed, and
the module's health turned red for a fault its author could only repair
after the fact. hq held the rule at the record's own merge. The review now
judges it ahead, before the judgement: such a decision stays proposed with
a changes finding naming the rule. It is not refused at propose, because
no record can link a number only reserved.

modules/mesh-knowledge/cmd/mesh-knowledge/kit_test.go

@@ -436,9 +436,13 @@ func valid(n int) ProposeAsk {
 			{Name: "Consequences", Text: "Merges land sooner."},
 			{Name: "How it is checked", Text: "The controller's merge-window tests."},
 		},
-		Links: []LinkAsk{{Kind: LinkExtends, To: "0276"}, {Kind: LinkChanges, To: "0276 §1", From: 1}}}
+		Links: []LinkAsk{{Kind: LinkExtends, To: "0276"}, {Kind: LinkChanges, To: "0276 §1", From: 1}},
+		Homes: []string{testHome}}
 }
 
+// testHome is the hq design valid names as its home: a decision is accepted only cited (novox/hq issue 504).
+const testHome = "03-DESIGN/01-to-be/55-the-knowledge-base.md"
+
 // imported is a world whose knowledge base holds the fixture's records.
 func imported(t *testing.T, s Store) *world {
 	t.Helper()