Harden semantic boundaries and repair dialogue state

Replace nearest-neighbour personal routing with a frozen class-balanced linear head measured on historical, stratified, cross-validation, holdout, and fresh challenge gates (V-702). Close the four repair handoff holes, preserve nested clarification flows, and route Russian possession statements through structural grammar rather than lexical exceptions (V-573). Owner explicitly requested direct commits to master.

cmd/labelgen/main.go

@@ -40,34 +40,19 @@ type label struct {
 	Labeled   bool   `json:"labeled"`
 }
 
-// grammars mirrors buildRouter's order in cmd/mavend/voicewire.go. Order is
-// load-bearing there and so it is here: the agenda rules must sit after the
-// clock rules, Praxis before the capture marker, the narrative rules last.
+// grammars is the daemon's canonical ordered stage-zero set. Label generation
+// must not maintain a second copy: that drift was the defect fixed by V-693.
 func grammars() []router.Grammar {
-	var g []router.Grammar
-	g = append(g, router.SystemTimeDateGrammars()...)
-	g = append(g, router.AgendaQueryGrammars()...)
-	g = append(g, router.FeedQueryGrammar())
-	g = append(g, router.TaskListGrammar())
-	g = append(g, router.ListGrammars()...)
-	g = append(g, router.ReminderGrammar())
-	g = append(g, router.PraxisGrammars()...)
-	g = append(g, router.TaskCaptureGrammar())
-	g = append(g, router.NarrativeQueryGrammars()...)
-	return g
+	return router.StageZeroGrammars(router.DefaultActMatcher{})
 }
 
 func match(gs []router.Grammar, utterance string) label {
 	out := label{Utterance: utterance}
 	for _, g := range gs {
-		m := g.Pattern.FindStringSubmatch(utterance)
-		if m == nil {
+		d, matched, ok := g.Evaluate(utterance)
+		if !matched || !ok {
 			continue
 		}
-		d, ok := g.Build(m)
-		if !ok {
-			continue // the rule saw its shape and declined it
-		}
 		out.Intent = string(d.Intent)
 		out.Grammar = g.Name
 		out.Key = d.Slots.Key