Move a module on a merge only when its build source holds a changed file (hq ADR 0267, issue 363)

Every merge to the controller's repository planned the controller, the
build seat's holder and the route proxy in three gated tiers, whatever it
changed (issue 338). The planner now maps a merge's files onto the build
source each module's newest trunk build said: a README moves nothing, the
controller's command the controller alone, the proxy's program the proxy
alone. A module with none said, or one an open plan has yet to build, is
read whole as before. Sharing a repository draws no packages edge any more,
and one recorded before neither widens nor orders a plan.

cmd/mesh-controller/order_test.go

@@ -157,7 +157,7 @@ func TestAMergeRebuildsTheModulesItChanged(t *testing.T) {
 		{"a file directly among the modules", merge([]string{"modules/README.md"}, false), ""},
 		{"a root file beside a module's", merge([]string{"merge-check.sh", "modules/keycloak/x.ts"}, false), "keycloak"},
 	} {
-		if got := named(whatTheMergeTouched(candidates, known, c.m)); got != c.want {
+		if got := named(whatTheMergeTouched(candidates, known, c.m, nil)); got != c.want {
 			t.Errorf("%s: rebuilt %q, wanted %q", c.what, got, c.want)
 		}
 	}
@@ -285,7 +285,7 @@ func TestAChangeInsideAModuleIsThatModulesHeldOrNot(t *testing.T) {
 		{"an old announcer saying nothing", merge(showcase, nil, false), ""},
 		{"a manifest the merge removed, said or not", merge([]string{"modules/gone/module.json", "modules/gone/x.ts"}, nil, true), ""},
 	} {
-		if got := named(whatTheMergeTouched(candidates, known, c.m)); got != c.want {
+		if got := named(whatTheMergeTouched(candidates, known, c.m, nil)); got != c.want {
 			t.Errorf("%s: rebuilt %q, wanted %q", c.what, got, c.want)
 		}
 	}