router, mavend: a complaint about a thing is not a fact about him (V-481)

"сеть какая-то медленная" and "интернет не работает" were written as `self`
rows at confidence 1.00. Recall reads a self row back later as if it were
still true, and that is the class of row that outranked live search in #470 —
so a slow afternoon becomes a standing belief about his network.

IsTransientComplaint is the same shape as IsQuestionShaped: deterministic,
offline, and off by default in the two cases where losing a real capture would
cost more than keeping a complaint. An explicit "запомни ..." wins, because he
asked. A first-person marker wins, because "я сломал руку" is durable and the
test is meant for sentences about things.

She answers the turn as chat instead of storing it. actionChat now has the
same nil-phraser floor the other model callers have.

The second defect filed here — a reply body of literally "{" — was closed by
the errBrokenJSON path in V-397 and needs nothing further.

cmd/mavend/factgate_test.go

@@ -123,3 +123,48 @@ func mustEmbedPassage(t *testing.T, h *reactiveHandler, text string) []float32 {
 	}
 	return vec
 }
+
+// The write half of #481: a complaint about a thing is a state of the
+// afternoon, not a fact about him. Stored as a `self` row at confidence 1.00
+// it comes back on recall as if the network were still down.
+func TestActionFact_ComplaintIsNotWritten(t *testing.T) {
+	ctx := context.Background()
+	h, api := newFactGateHandler(t, time.Now())
+
+	reply := h.actionFact(ctx, router.Decision{
+		Intent:    router.IntentFact,
+		Utterance: "сеть какая-то медленная",
+		Slots:     router.Slots{Key: "network_speed", HasKey: true, Value: "медленная"},
+	})
+
+	if _, err := api.LatestFact(ctx, "network_speed"); err == nil {
+		t.Fatal("a passing complaint was stored as a fact about him")
+	}
+	hits, err := h.memStore.Search(ctx, mustEmbedPassage(t, h, "сеть какая-то медленная"), 3)
+	if err != nil {
+		t.Fatalf("memory search: %v", err)
+	}
+	if len(hits) != 0 {
+		t.Fatalf("the complaint was indexed for recall: %+v", hits)
+	}
+	if reply == "" {
+		t.Fatal("the turn was neither stored nor answered")
+	}
+}
+
+// And the complaint he asked her to keep: the capture verb wins, as it does
+// over the question gate.
+func TestActionFact_AskedToRememberAComplaintStillWrites(t *testing.T) {
+	ctx := context.Background()
+	h, api := newFactGateHandler(t, time.Now())
+
+	h.actionFact(ctx, router.Decision{
+		Intent:    router.IntentFact,
+		Utterance: "запомни что интернет не работает",
+		Slots:     router.Slots{Key: "internet", HasKey: true, Value: "не работает"},
+	})
+
+	if _, err := api.LatestFact(ctx, "internet"); err != nil {
+		t.Fatalf("an explicit capture was refused: %v", err)
+	}
+}