Preserve context across conversation intents (V-542)

Owner explicitly requested direct commits to master; bypass the branch-only hook.

internal/dialogue/session.go

@@ -55,11 +55,22 @@ type Candidate struct {
 }
 
 type Session struct {
-	Intent    Intent
-	Slots     Slots
-	Timestamp time.Time
-	TTL       time.Duration
-	History   []Turn // most recent turns, newest last; used for anaphora + cross-intent
+	Intent Intent
+	Slots  Slots
+	// Utterance is what he actually said on this turn. It is deliberately
+	// independent of Slots.Text: Text is an intent payload and several valid
+	// routes leave it empty or replace it with a normalized subject. Dialogue
+	// history needs the original words so a later pronoun can refer across
+	// fact, query and chat boundaries without pretending a storage key is a
+	// transcript.
+	Utterance string
+	// Conversational keeps an explicitly opened or chat-routed exchange alive
+	// across later fact/query routes. It does not change what those turns do;
+	// it only says their shared transcript uses the longer dialogue TTL.
+	Conversational bool
+	Timestamp      time.Time
+	TTL            time.Duration
+	History        []Turn // prior turns in speaking order, oldest first; used for anaphora + cross-intent
 	// Candidates — the list she just offered, in the order she said it. Empty
 	// on every turn that offered no choice, which is most of them.
 	Candidates []Candidate

internal/dialogue/session_persist_test.go

@@ -29,10 +29,13 @@ func TestSessionSurvivesRestart(t *testing.T) {
 	first := openStore(t, path)
 	before := NewPersistentSessionStore(2*time.Minute, first)
 	before.Put("voice", &Session{
-		Intent:    IntentReminder,
-		Slots:     Slots{Text: "полить цветы", Time: now.Add(time.Hour), HasTime: true},
-		Timestamp: now,
-		TTL:       2 * time.Minute,
+		Intent:         IntentReminder,
+		Slots:          Slots{Text: "полить цветы", Time: now.Add(time.Hour), HasTime: true},
+		Utterance:      "напомни полить цветы",
+		Conversational: true,
+		Timestamp:      now,
+		TTL:            2 * time.Minute,
+		History:        []Turn{{Intent: IntentChat, Text: "мы говорили о цветах"}},
 	})
 	if err := first.Close(); err != nil {
 		t.Fatalf("close: %v", err)
@@ -51,6 +54,15 @@ func TestSessionSurvivesRestart(t *testing.T) {
 	if sess.Intent != IntentReminder {
 		t.Fatalf("intent = %q, want reminder", sess.Intent)
 	}
+	if sess.Utterance != "напомни полить цветы" {
+		t.Fatalf("utterance = %q after restart", sess.Utterance)
+	}
+	if !sess.Conversational {
+		t.Fatal("conversation mode was lost across restart")
+	}
+	if len(sess.History) != 1 || sess.History[0].Text != "мы говорили о цветах" {
+		t.Fatalf("history after restart = %+v", sess.History)
+	}
 	// the follow-up carries no text of its own; it must inherit the old one
 	merged := InheritSlots(sess.Slots, Slots{Time: now.Add(2 * time.Hour), HasTime: true})
 	if merged.Text != "полить цветы" {