dialogue, tasks: carry the list she just read (V-448)

Session.Candidates holds what she offered, in the order she offered it, and
SetCandidates attaches it in place so the turn already remembered keeps its
slots. tasks.Spoken is the list FormatRU actually named, so an ordinal and
the spoken order cannot drift apart.

docs/design.md

@@ -223,6 +223,24 @@ Not alternatives — layers:
 Router contract: `[{"intent":<enum>, key?, value?, text?, verb?}, ...]` over
 7 intents (`fact, reminder, note, query, act, chat, system`).
 
+#### "второй" points at the list she just read
+
+Landed 2026-08-04 (Vikunja #448). The dialogue session carried the intent, the
+slots and the history, and not the list. She recited five tasks, he said
+"второй", and the word had nothing to point at.
+
+`Session.Candidates` holds what she just offered, bound at the moment she speaks
+it and in the order she speaks it (`tasks.Spoken`). Binding afterwards would
+resolve the word against a fresh query, and the list changes between two turns.
+`cmd/mavend/ordinal.go` reads the position before routing and dispatches on the
+candidate's kind.
+
+An ordinal with no verb is read back, not acted on — "второй" names a task, it
+does not say what to do with it. With a verb ("первую сделал", "последнюю
+убери") the task moves and the list is spent, because a second ordinal against a
+list that no longer holds closes the wrong work. A position she never read is
+answered with how many she did read, not routed as a fresh sentence.
+
 #### Saying she got it wrong is a feature
 
 Landed 2026-08-04 (Vikunja #455). `Router.CorrectMisroute` could always append a