feat(elder): @Elder merges a thread's delivers when asked (#26)

nestapi.go

@@ -28,9 +28,14 @@ KIND: deliver (here is the result)
 KIND: decline (with a reason)
 Then, on the next line, your message text.`
 
-// nestMembers lists who may be addressed in a nest: its crows plus the owner.
+// serviceRoles are addressable in a nest but never members: they only act when
+// a crow's or the owner's message asks them to.
+var serviceRoles = []string{"Elder"}
+
+// nestMembers lists who may be addressed in a nest: its crows, the owner, and
+// the service roles.
 func nestMembers(nest Nest) []string {
-	return append(append([]string{}, nest.Crows...), "owner")
+	return append(append(append([]string{}, nest.Crows...), "owner"), serviceRoles...)
 }
 
 func (s *Server) getNestMessages(w http.ResponseWriter, r *http.Request) {
@@ -179,6 +184,8 @@ func (s *Server) postNestMessage(w http.ResponseWriter, r *http.Request) {
 		switch {
 		case mode == "conspiracy" && invited > 0:
 			go s.respondConspiracy(nest, record, invited)
+		case record.To == "Elder":
+			go s.respondElder(nest, record)
 		case slices.Contains(nest.Crows, record.To):
 			go s.respondToRequest(nest, record)
 		}
@@ -308,6 +315,48 @@ func (s *Server) respondOne(nest Nest, req Message, crow string, lens bool) {
 	}
 }
 
+// respondElder merges the reports on a thread: the Elder only speaks when a
+// message asks it to (CHATROOM_SPEC section 6 — synthesis is requested, not a
+// fixed step). It answers whoever opened the thread it merges.
+func (s *Server) respondElder(nest Nest, req Message) {
+	if req.RefersTo == "" {
+		return
+	}
+	target, found := s.msgs.ByMsgID(req.RefersTo)
+	if !found {
+		return
+	}
+	var reports []string
+	for _, m := range s.msgs.ReportsTo(nest.ID, target.MsgID(), "deliver") {
+		if slices.Contains(nest.Crows, m.Author) {
+			reports = append(reports, "["+m.Author+"] "+m.Text)
+		}
+	}
+	if len(reports) == 0 {
+		return
+	}
+	budget := &Budget{name: "elder-merge", limit: s.p.G.TokenBudgetPerItem}
+	system := systemFor("Elder", elderSystem, true)
+	prompt := "REQUEST: " + target.Text + "\n--- reports to merge ---\n" + strings.Join(reports, "\n--- \n")
+	answer, err := s.p.Flock.ask(s.ctx, nil, "Elder", system, prompt, budget)
+	if err != nil {
+		return
+	}
+	reply := Message{
+		NestID:    nest.ID,
+		Kind:      "deliver",
+		Author:    "Elder",
+		Text:      strings.TrimSpace(answer),
+		To:        target.Author,
+		RefersTo:  target.MsgID(),
+		TaggedBy:  "harness",
+		Timestamp: time.Now().UTC().Format(time.RFC3339),
+	}
+	if record, err := s.msgs.Append(reply); err == nil {
+		s.emitNestMessage(record)
+	}
+}
+
 // checkDivergence asks Jev whether this deliver restates earlier delivers that
 // answer the same request. Above the band the crow gets a review nudge; the
 // deliver itself stays in the log (nudges never silence).