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/mavend/clarify.go

@@ -342,7 +342,7 @@ func (h *reactiveHandler) resolveClarifyAnswer(ctx context.Context, text string)
 
 	switch role {
 	case roleCancel:
-		h.clarifyStore.Delete(dialogueIDOf(ctx))
+		h.completeClarifyTop(ctx)
 		return clarifyCancelled, true
 	case roleSideQuery:
 		// He asked something of his own WITHOUT leaving the flow. The question
@@ -419,8 +419,6 @@ func (h *reactiveHandler) resolveClarifyAnswer(ctx context.Context, text string)
 	if stillOpen(q.Missing, whenTextOf(q), merged) {
 		return h.reaskOrGiveUp(ctx, q, merged, text, taken), true
 	}
-	h.clarifyStore.Delete(dialogueIDOf(ctx))
-
 	// One gap filled is not the same as a complete request. askClarify parks
 	// only the first gap, because one question per turn is the rule, but a
 	// reminder wants both a subject and a time. "напомни" with neither used to
@@ -431,6 +429,7 @@ func (h *reactiveHandler) resolveClarifyAnswer(ctx context.Context, text string)
 	if reply, asked := h.askRemainingGap(ctx, q, intent, merged); asked {
 		return reply, true
 	}
+	h.completeClarifyTop(ctx)
 
 	// Rebuild the decision as if it had routed cleanly, then run it down the
 	// normal path. Clarify is deliberately false and the intent is unchanged:
@@ -446,6 +445,27 @@ func (h *reactiveHandler) resolveClarifyAnswer(ctx context.Context, text string)
 	return h.finishClarified(ctx, dec), true
 }
 
+// completeClarifyTop finishes only the active question. A nested question can
+// sit above a flow that was suspended by a side request or repair; deleting the
+// dialogue id here erased both. If one survives underneath, restart its clock
+// from the moment it is spoken again and attach its question to this turn.
+func (h *reactiveHandler) completeClarifyTop(ctx context.Context) {
+	if h.clarifyStore == nil {
+		return
+	}
+	_, resumed := h.clarifyStore.CompleteTop(dialogueIDOf(ctx), h.now())
+	if resumed == nil || len(resumed.Missing) == 0 {
+		return
+	}
+	question, ok := clarifyResumedFor(resumed.Missing[0])
+	if !ok {
+		return
+	}
+	if rt := turnRouteFrom(ctx); rt != nil {
+		rt.resume = question
+	}
+}
+
 // noteDropped records that the parked request was let go this turn, so runTurn
 // can say it in front of whatever these words are answered with. Nothing to
 // record outside runTurn — a unit test calling one resolver has no turn to glue
@@ -487,7 +507,7 @@ func (h *reactiveHandler) noteSuspended(ctx context.Context, q *dialogue.Pending
 		return
 	}
 	if !q.CanResume() {
-		h.clarifyStore.Delete(dialogueIDOf(ctx))
+		h.completeClarifyTop(ctx)
 		h.noteDropped(ctx)
 		log.Printf("voice: clarify — letting the question about %s go: %d asides in a row, %d rides in all", q.Missing[0], q.Suspends, q.Rides)
 		return
@@ -576,7 +596,7 @@ func (h *reactiveHandler) reaskOrGiveUp(ctx context.Context, q *dialogue.Pending
 		question, _ = h.questionFor(q.Missing[0], q.Attempts+1, whenTextOf(q), merged, taken)
 	}
 	if question == "" || !q.CanAsk() {
-		h.clarifyStore.Delete(dialogueIDOf(ctx))
+		h.completeClarifyTop(ctx)
 		log.Printf("voice: clarify — gave up on %v after %d question(s), answer was %q", q.Missing, q.Attempts, text)
 		return clarifyGaveUp
 	}
@@ -590,15 +610,38 @@ func (h *reactiveHandler) reaskOrGiveUp(ctx context.Context, q *dialogue.Pending
 	return question
 }
 
-// finishClarified runs a completed decision through the same steps a freshly
-// routed one takes: remember the turn, act, then phrase.
+// finishClarified completes a decision whose parked gaps were already checked
+// by resolveClarifyAnswer. It still records the turn for a later correction;
+// the old path made anything completed through dialogue uncorrectable (V-573).
 func (h *reactiveHandler) finishClarified(ctx context.Context, dec router.Decision) string {
+	return h.finishRebuilt(ctx, dec, false)
+}
+
+// finishRepaired validates a decision rebuilt from an older utterance. Unlike
+// resolveClarifyAnswer, repair has not passed the current slot gate, so it must
+// ask about any missing argument before acting (V-573).
+func (h *reactiveHandler) finishRepaired(ctx context.Context, dec router.Decision) string {
+	return h.finishRebuilt(ctx, dec, true)
+}
+
+func (h *reactiveHandler) finishRebuilt(ctx context.Context, dec router.Decision, validate bool) string {
+	if validate && (dec.Clarify || len(missingFor(dec)) > 0) {
+		if reply := h.hexisBeforeClarify(ctx, dec); reply != "" {
+			return reply
+		}
+		if question, asked := h.askClarify(ctx, dec); asked {
+			return question
+		}
+	}
 	if h.dialogueSessions != nil {
 		now := h.now()
 		prev := h.dialogueSessions.Get(dialogueIDOf(ctx), now)
 		dec = followUpMerge(prev, dec, now)
 		h.rememberTurn(ctx, prev, dec, now)
 	}
+	if !dec.Clarify {
+		h.recordTurn(dec.Utterance, dec.Intent)
+	}
 	reply := h.applyAction(ctx, dec)
 	if reply == "" {
 		reply = h.replier.Reply(ctx, dec)