Nests: team rooms with core crows and borrowing

- Server: nests API, persistence, core-first picking, borrowed flag
  (built by the backend agent against EVENTS.md; tests pass with -race)
- UI: nests in the sidebar, one feed per nest, header shows the core
  team, New nest dialog, borrowed crows labeled, per-nest waiting count
- start.command: one-click local server in controlled mode (mock crows,
  localhost only, state in .crows/)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UQnSw4RRWp8uqpj3nsnnXF

server.go

@@ -31,12 +31,13 @@ type Server struct {
 	p        *Pipeline
 	approver *WebApprover
 	hub      *Hub
+	nests    *NestStore
 	ctx      context.Context // cancelled on shutdown; lists and streams end with it
 	beat     time.Duration
 }
 
-func NewServer(ctx context.Context, p *Pipeline, approver *WebApprover) *Server {
-	return &Server{p: p, approver: approver, hub: NewHub(), ctx: ctx, beat: heartbeat}
+func NewServer(ctx context.Context, p *Pipeline, approver *WebApprover, nests *NestStore) *Server {
+	return &Server{p: p, approver: approver, hub: NewHub(), nests: nests, ctx: ctx, beat: heartbeat}
 }
 
 func (s *Server) Handler() http.Handler {
@@ -45,6 +46,8 @@ func (s *Server) Handler() http.Handler {
 	mux.HandleFunc("GET /api/events", s.events)
 	mux.HandleFunc("POST /api/verdicts", s.postVerdict)
 	mux.HandleFunc("GET /api/trust", s.trust)
+	mux.HandleFunc("GET /api/nests", s.getNests)
+	mux.HandleFunc("POST /api/nests", s.postNest)
 	if st, err := os.Stat(webDir); err == nil && st.IsDir() {
 		mux.Handle("GET /", http.FileServer(http.Dir(webDir)))
 	} else {
@@ -67,13 +70,15 @@ func cmdServe(args []string) {
 	flog, err := OpenFlightLog(filepath.Join(dataDir, "flight.jsonl"))
 	must(err)
 	defer flog.Close()
+	nests, err := LoadNests(filepath.Join(dataDir, "nests.json"))
+	must(err)
 
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer stop()
 	brain := NewBrain()
 	approver := NewWebApprover(*timeout)
 	p := &Pipeline{Flock: NewFlock(brain, g, flog), Ledger: ledger, Log: flog, G: g, Approver: approver}
-	s := NewServer(ctx, p, approver)
+	s := NewServer(ctx, p, approver, nests)
 
 	srv := &http.Server{Addr: *addr, Handler: s.Handler(), ReadHeaderTimeout: 10 * time.Second}
 	go func() {
@@ -120,10 +125,19 @@ func (s *Server) postList(w http.ResponseWriter, r *http.Request) {
 	var body struct {
 		Text      string `json:"text"`
 		Requester string `json:"requester"`
+		NestID    string `json:"nest_id"`
 	}
 	if !decode(w, r, &body) {
 		return
 	}
+	if body.NestID == "" {
+		body.NestID = defaultNestID
+	}
+	nest, found := s.nests.Get(body.NestID)
+	if !found {
+		httpError(w, http.StatusNotFound, fmt.Sprintf("There is no nest called %q.", body.NestID))
+		return
+	}
 	if body.Requester == "" {
 		body.Requester, _, _ = net.SplitHostPort(r.RemoteAddr)
 	}
@@ -157,7 +171,7 @@ func (s *Server) postList(w http.ResponseWriter, r *http.Request) {
 
 	id := newListID()
 	s.hub.Open(id, body.Requester)
-	l := List{ID: id, Requester: body.Requester, Source: "web", Items: items, Parallel: true}
+	l := List{ID: id, Requester: body.Requester, Source: "web", Items: items, Nest: nest, Parallel: true}
 	go s.p.Run(s.ctx, l, s.hub.Emitter(id))
 	writeJSON(w, http.StatusAccepted, map[string]string{"list_id": id})
 }
@@ -253,3 +267,29 @@ func (s *Server) trust(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "application/json")
 	w.Write(data)
 }
+
+func (s *Server) getNests(w http.ResponseWriter, r *http.Request) {
+	writeJSON(w, http.StatusOK, map[string]any{"roster": roster, "nests": s.nests.All()})
+}
+
+func (s *Server) postNest(w http.ResponseWriter, r *http.Request) {
+	var body struct {
+		Name  string   `json:"name"`
+		Crows []string `json:"crows"`
+	}
+	if !decode(w, r, &body) {
+		return
+	}
+	n, err := s.nests.Create(body.Name, body.Crows)
+	var bad *NestError
+	switch {
+	case errors.As(err, &bad) && bad.Clash:
+		httpError(w, http.StatusConflict, bad.Msg)
+	case errors.As(err, &bad):
+		httpError(w, http.StatusBadRequest, bad.Msg)
+	case err != nil:
+		httpError(w, http.StatusInternalServerError, "could not save the nest: "+err.Error())
+	default:
+		writeJSON(w, http.StatusCreated, n)
+	}
+}