J3 (A2f findings 2, 4): a leaving module's accepted event is named by its module; a user naming no series accepts the first numbered one

ManifestAccepted.EventID names the module when the digest is empty, so the indexer's own id for a module leaving the
trunk can go and the id lives in one place. Manifest.AcceptedSeries takes the series the package has a numbered
version in and answers the lowest, the series of its first numbered version (design 32), DefaultSeries while none is.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

go/catalogue/config_test.go

@@ -145,6 +145,7 @@ func TestAConfigManifestIsWrittenBackInItsOwnForm(t *testing.T) {
 	}
 	if m.Settings["font"].RenamedFrom != "font-name" || m.AcceptedSeries("mesh-sdk") != "0.2" ||
 		m.AcceptedSeries("mesh-contracts") != DefaultSeries || m.Build.Artifacts[0].SeriesOf() != "0.2" ||
+		m.AcceptedSeries("mesh-sdk", "0.1") != "0.2" || m.AcceptedSeries("mesh-contracts", "0.10", "x", "0.3", "1.0") != "0.3" ||
 		m.Build.Artifacts[0].GeneratedFrom != "seats" || m.Build.Artifacts[1].SeriesOf() != "0.1" {
 		t.Fatalf("read %+v", m)
 	}

go/catalogue/manifest.go

@@ -1243,13 +1243,39 @@ type Artifact struct {
 	GeneratedFrom string `json:"generated-from,omitempty"`
 }
 
-// AcceptedSeries is the series of the package of that name this module accepts: the one Packages names, or
-// DefaultSeries.
-func (m Manifest) AcceptedSeries(name string) string {
+// AcceptedSeries is the series of the package of that name this module accepts: the one Packages names, or else the
+// series of the package's first numbered version (design 32), the lowest of numbered, the series the package has a
+// numbered version in (the indexer's to say; a series is only ever raised); DefaultSeries while none is numbered.
+func (m Manifest) AcceptedSeries(name string, numbered ...string) string {
 	if s := m.Packages[name]; s != "" {
 		return s
 	}
-	return DefaultSeries
+	first := ""
+	for _, s := range numbered {
+		if seriesOrder(s) != nil && (first == "" || compareSeries(s, first) < 0) {
+			first = s
+		}
+	}
+	if first == "" {
+		return DefaultSeries
+	}
+	return first
+}
+
+// seriesOrder is a series' major and minor, or nil when it is no `<major>.<minor>`.
+func seriesOrder(s string) []int {
+	major, minor, ok := strings.Cut(s, ".")
+	a, err1 := strconv.Atoi(major)
+	b, err2 := strconv.Atoi(minor)
+	if !ok || err1 != nil || err2 != nil || a < 0 || b < 0 {
+		return nil
+	}
+	return []int{a, b}
+}
+
+// compareSeries orders two well-formed series by major, then minor.
+func compareSeries(a, b string) int {
+	return slices.Compare(seriesOrder(a), seriesOrder(b))
 }
 
 // DefaultSeries is the series of an artifact or an accepted package that names none (design 32).

go/delivery/verdicts.go

@@ -234,7 +234,11 @@ func AcceptedOf(digest string, v ManifestVerdict, m catalogue.Manifest) Manifest
 }
 
 // EventID is the event's id, one per manifest digest and judge, so the bus takes it once:
-// `manifest-accepted-<digest>-<judge>`.
+// `manifest-accepted-<digest>-<judge>`. The empty one of a module leaving the trunk carries no digest, so it is named by
+// its module: `manifest-accepted-left-<module>-<judge>`.
 func (a ManifestAccepted) EventID() string {
+	if a.Digest == "" {
+		return ManifestAcceptedEvent + "-left-" + a.Module + "-" + a.Judge
+	}
 	return ManifestAcceptedEvent + "-" + a.Digest + "-" + a.Judge
 }

go/delivery/verdicts_test.go

@@ -103,6 +103,11 @@ func TestAManifestVerdictIsTheContractReadersTake(t *testing.T) {
 	if id := heard.EventID(); id != "manifest-accepted-"+digest+"-src2:j" {
 		t.Fatalf("the accepted event's id is %q", id)
 	}
+	// The empty one of a module leaving the trunk has no digest: its id names the module, so two modules' differ.
+	if a, b := (ManifestAccepted{Module: "a", Judge: "j"}).EventID(), (ManifestAccepted{Module: "b", Judge: "j"}).EventID(); a == b ||
+		a != "manifest-accepted-left-a-j" {
+		t.Fatalf("the ids of two modules leaving are %q and %q", a, b)
+	}
 	// Both verdict events carry the indexer's revision (ADR 0622 §2), and one without it reads as revision 0.
 	for _, ev := range []any{ManifestAccepted{Module: "m", Revision: 41}, ManifestRefused{Module: "m", Revision: 41}} {
 		raw, _ := json.Marshal(ev)