mesh-issues: a take-over note records who acted, not the worker named; tests for the remaining rules (hq issue 399)

The note's by is who acted as the runtime proves it (ADR 0275 §5); the
note's text names both workers. Tests for a resolved issue corrected, link
and set keeping the worker current, and a take-over reason with a secret's
shape. The ready-to-verify note says an issue resolves from fixing.

modules/mesh-issues/cmd/mesh-issues/tracker_test.go

@@ -303,6 +303,7 @@ func TestTheCyclesRulesHoldAtTheWrite(t *testing.T) {
 		{"take-over on another status", []string{"hq"}, "", MoveAsk{Status: StatusLocated, TakeOver: "x"}, "take-over is for"},
 		{"take-over with nobody to take from", nil, "", MoveAsk{Status: StatusFixing, By: "a@g14", TakeOver: "x"}, "nobody works on"},
 		{"an amended design that is not one", nil, "", MoveAsk{Status: StatusDiagnosing, By: "a@g14", AmendedDesign: []string{"../etc/passwd"}}, "not a design document"},
+		{"a take-over reason that carries a secret", nil, StatusDiagnosing, MoveAsk{Status: StatusFixing, By: "b@ace", TakeOver: "the key is sk-ant-api03-abcdefghijklmnopqrstuvwxyz"}, "carries no secret"},
 		{"a fixed-by of two lines", []string{"hq"}, fx, MoveAsk{Status: StatusResolved, FixedBy: []string{"a\nb"}}, "one line"},
 	}
 	for _, c := range cases {