/trace grows a turn-decisions table under the rule trace (V-564)

Both tables answer the same question, who won and who lost, one about nudges
and the other about utterances, so they share a page rather than splitting the
nav. A turn is one collapsible row; never_asked is coloured like a block,
because it usually is one. A read failure is logged and the rule trace above it
still renders: a daemon too old to know the method is the ordinary case during
a rolling deploy.

cmd/mavweb/main.go

@@ -1415,12 +1415,29 @@ func handleTrace(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
 		http.Error(w, "core read failed", http.StatusBadGateway)
 		return
 	}
+	// The turn records share this page rather than getting one of their own
+	// (V-564): both answer the same question — who won, who lost and why — and
+	// one is about nudges while the other is about utterances. A read failure
+	// here is not fatal to the page: the rule trace above it still renders, and
+	// a daemon too old to know the method is the ordinary case during a rolling
+	// deploy.
+	turns, err := core.TurnDecisions(ctx, 25)
+	if err != nil {
+		log.Printf("trace: turn decisions: %v", err)
+	}
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	if err := traceTmpl.Execute(w, trace); err != nil {
+	if err := traceTmpl.Execute(w, traceData{Tick: trace, Turns: turns}); err != nil {
 		log.Printf("trace render: %v", err)
 	}
 }
 
+// traceData — what trace.html renders: the last tick's rule arbitration and the
+// last turns' claim arbitration.
+type traceData struct {
+	Tick  ipc.TickTrace
+	Turns []ipc.TurnDecision
+}
+
 func handleMorning(w http.ResponseWriter, r *http.Request, core ipc.CoreAPI) {
 	if core == nil {
 		http.Error(w, "morning disabled (no -core)", http.StatusServiceUnavailable)