the dialogue session belongs to one reach, not to the box (V-45)

The clarify store was keyed per reach in V-466. The dialogue session was not:
five call sites read and wrote the constant voiceDialogueID, so anaphora,
history and the ordinal candidate list were one slot for the whole daemon.

The candidate list is the half that cost something. She recites tasks at the
mic, he types "первую сделал" on /chat, and it closes the second task he heard
out loud on a surface that never showed him a list. Now every one of those
sites reads dialogueIDOf(ctx), which handleText and the voice path already set.

resolveCandidate also wrote resolved_by "tap:voice" for every pick, including a
typed one. It takes the turn's source now. A row that lies about where it came
from is worse than no row.

Anaphora across surfaces was the other reading — one continuous conversation
with her, any surface. Rejected: a phone open while he talks is the case this
box hits, and two clients sharing one slot trample each other.

cmd/mavend/ordinal_test.go

@@ -38,7 +38,7 @@ func TestParseOrdinalReadsThePosition(t *testing.T) {
 
 func TestOrdinalPassesWithNothingOffered(t *testing.T) {
 	h, _, _ := newClarifyHandler(t)
-	if _, handled := h.resolveCandidate(context.Background(), "второй"); handled {
+	if _, handled := h.resolveCandidate(context.Background(), "второй", sourceVoice); handled {
 		t.Error("an ordinal with no list behind it was claimed")
 	}
 }
@@ -47,14 +47,14 @@ func TestOrdinalReadsBackWithoutAVerb(t *testing.T) {
 	h, st, _ := newClarifyHandler(t)
 	ctx := context.Background()
 	ids := seedTasks(t, st, "купить хлеб", "позвонить маме")
-	putCandidates(h, ids, "купить хлеб", "позвонить маме")
+	putCandidates(h, context.Background(), ids, "купить хлеб", "позвонить маме")
 
-	reply, handled := h.resolveCandidate(ctx, "второй")
+	reply, handled := h.resolveCandidate(ctx, "второй", sourceVoice)
 	if !handled || !strings.Contains(reply, "позвонить маме") {
 		t.Fatalf("a bare ordinal did not read the task back: %q handled=%v", reply, handled)
 	}
 	// Still live: naming one is often the first half of a sentence.
-	if _, handled := h.resolveCandidate(ctx, "первый"); !handled {
+	if _, handled := h.resolveCandidate(ctx, "первый", sourceVoice); !handled {
 		t.Error("the list was spent by a read-back")
 	}
 }
@@ -63,9 +63,9 @@ func TestOrdinalWithAVerbMovesTheTask(t *testing.T) {
 	h, st, _ := newClarifyHandler(t)
 	ctx := context.Background()
 	ids := seedTasks(t, st, "купить хлеб", "позвонить маме")
-	putCandidates(h, ids, "купить хлеб", "позвонить маме")
+	putCandidates(h, context.Background(), ids, "купить хлеб", "позвонить маме")
 
-	reply, handled := h.resolveCandidate(ctx, "первую сделал")
+	reply, handled := h.resolveCandidate(ctx, "первую сделал", sourceVoice)
 	if !handled || !strings.Contains(reply, "купить хлеб") {
 		t.Fatalf("the pick was not acted on: %q handled=%v", reply, handled)
 	}
@@ -80,7 +80,7 @@ func TestOrdinalWithAVerbMovesTheTask(t *testing.T) {
 	}
 	// Spent: a second ordinal against a list that no longer holds would close
 	// the wrong task.
-	if _, handled := h.resolveCandidate(ctx, "второй"); handled {
+	if _, handled := h.resolveCandidate(ctx, "второй", sourceVoice); handled {
 		t.Error("the list survived the pick it was spent on")
 	}
 }
@@ -88,9 +88,9 @@ func TestOrdinalWithAVerbMovesTheTask(t *testing.T) {
 func TestOrdinalPastTheEndSaysHowMany(t *testing.T) {
 	h, st, _ := newClarifyHandler(t)
 	ids := seedTasks(t, st, "купить хлеб")
-	putCandidates(h, ids, "купить хлеб")
+	putCandidates(h, context.Background(), ids, "купить хлеб")
 
-	reply, handled := h.resolveCandidate(context.Background(), "третий")
+	reply, handled := h.resolveCandidate(context.Background(), "третий", sourceVoice)
 	if !handled || !strings.Contains(reply, "1") {
 		t.Fatalf("a position she never read was not answered: %q handled=%v", reply, handled)
 	}
@@ -118,11 +118,13 @@ func seedTasks(t *testing.T, st *store.Store, texts ...string) []int64 {
 	return ids
 }
 
-func putCandidates(h *reactiveHandler, ids []int64, labels ...string) {
+// putCandidates binds a list to the reach the ctx names, the way queryTasks
+// does when she recites one.
+func putCandidates(h *reactiveHandler, ctx context.Context, ids []int64, labels ...string) {
 	cands := make([]dialogue.Candidate, 0, len(ids))
 	for i, id := range ids {
 		cands = append(cands, dialogue.Candidate{Kind: "task", Ref: id, Label: labels[i]})
 	}
-	h.dialogueSessions.Put(voiceDialogueID, &dialogue.Session{Timestamp: h.now()})
-	h.offerCandidates(cands)
+	h.dialogueSessions.Put(dialogueIDOf(ctx), &dialogue.Session{Timestamp: h.now()})
+	h.offerCandidates(ctx, cands)
 }