S1: seat settle gains a delayed nak and its capability, for a step given again (issue 1748)

Claude-Session: https://claude.ai/code/session_01JG73KEq4zoDfM9WtYpcQgZ

go/seat.go

@@ -86,8 +86,15 @@ const (
 	SettleNak      = "nak"
 	SettleTerm     = "term"
 	SettleProgress = "progress"
+	// SettleNakAfter hands the message back to be delivered again after a delay (SeatSettleAfter): the bus's own
+	// delayed redelivery, so no part keeps a timer for it.
+	SettleNakAfter = "nak-after"
 )
 
+// CapSeatSettleDelay is the capability a tool runner states when it applies SettleNakAfter; a module that settles with
+// it asks it in its manifest's capabilities, so its want waits on a node whose runner does not state it.
+const CapSeatSettleDelay = "seat-settle-delay"
+
 // SeatPull pulls at most one message from a held seat's worker the module's membership lists, waiting at most wait
 // (none when 0, at most 25 s): nil when none came. Unlike SeatTake nothing is fetched ahead: a build module pulls an
 // ask only when it has a free slot (novox/hq ADR 0525 §4; issue 1887 A11). A message never settled is delivered again
@@ -124,6 +131,17 @@ func SeatSettle(id, fate string) error {
 	return err
 }
 
+// SeatSettleAfter hands the message pulled under id back to be delivered again after delay (SettleNakAfter). The
+// runtime refuses a delay of 0 or below; a runtime that does not state CapSeatSettleDelay refuses the fate.
+func SeatSettleAfter(id string, delay time.Duration) error {
+	c, err := live()
+	if err != nil {
+		return err
+	}
+	_, err = c.ask("mesh/seat.settle", map[string]any{"id": id, "fate": SettleNakAfter, "delay_ms": delay.Milliseconds()}, seatTimeout)
+	return err
+}
+
 // SeatRecord reads one key of a record a seat keeps for this module, under its own name, or nil.
 func SeatRecord(bucket, key string) (*StateEntry, error) {
 	c, err := live()

go/seat_pull_test.go

@@ -23,7 +23,10 @@ func TestABundlePullsAndSettlesThroughTheRuntime(t *testing.T) {
 				return nil, err
 			}
 			got <- p
-			return map[string]any{}, SeatSettle(p.ID, SettleAck)
+			if err := SeatSettle(p.ID, SettleAck); err != nil {
+				return nil, err
+			}
+			return map[string]any{}, SeatSettleAfter("p2", time.Minute)
 		}}}, inR, outW)
 	}()
 	lines := bufio.NewScanner(outR)
@@ -59,8 +62,15 @@ func TestABundlePullsAndSettlesThroughTheRuntime(t *testing.T) {
 	}
 	asked = next()
 	params, _ = asked["params"].(map[string]any)
-	if asked["method"] != "mesh/seat.settle" || params["id"] != "p1" || params["fate"] != "ack" {
+	if asked["method"] != "mesh/seat.settle" || params["id"] != "p1" || params["fate"] != "ack" || params["delay_ms"] != nil {
 		t.Fatalf("settled %v", asked)
 	}
 	send(map[string]any{"jsonrpc": "2.0", "id": asked["id"], "result": map[string]any{}})
+	// S1 (issue 1748): a delayed nak names its fate and its delay in milliseconds.
+	asked = next()
+	params, _ = asked["params"].(map[string]any)
+	if asked["method"] != "mesh/seat.settle" || params["id"] != "p2" || params["fate"] != "nak-after" || params["delay_ms"] != 60000.0 {
+		t.Fatalf("settled after a delay %v", asked)
+	}
+	send(map[string]any{"jsonrpc": "2.0", "id": asked["id"], "result": map[string]any{}})
 }