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

main.go

@@ -36,7 +36,7 @@ func main() {
 func usage() {
 	fmt.Fprintln(os.Stderr, `So Many Crows
 
-  crows run <todo.txt> [-as name]   hand the flock a todo list
+  crows run <todo.txt> [-as name] [-nest id]  hand the flock a todo list
   crows serve [-addr 127.0.0.1:8080] run the web server (API + SSE)
   crows trust                       show trust ledger
   crows log [-n 20]                 show recent flight log entries`)
@@ -46,6 +46,7 @@ func usage() {
 func cmdRun(args []string) {
 	fs := flag.NewFlagSet("run", flag.ExitOnError)
 	as := fs.String("as", defaultRequester(), "requester id")
+	nestID := fs.String("nest", defaultNestID, "nest whose core crows fly first")
 	var pos []string
 	for fs.Parse(args); fs.NArg() > 0; fs.Parse(args) {
 		pos = append(pos, fs.Arg(0))
@@ -62,6 +63,12 @@ func cmdRun(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)
+	nest, found := nests.Get(*nestID)
+	if !found {
+		must(fmt.Errorf("there is no nest called %q", *nestID))
+	}
 	p := &Pipeline{Ledger: ledger, Log: flog, G: g, Approver: &StdinApprover{in: bufio.NewReader(os.Stdin)}}
 
 	if ok, msg, _ := ledger.Admit(*as, time.Now(), g); !ok {
@@ -86,8 +93,8 @@ func cmdRun(args []string) {
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer stop()
 
-	fmt.Printf("Brain: %s · requester: %s · %d items\n", brain.Name(), *as, len(items))
-	l := List{ID: "cli", Requester: *as, Source: todoPath, Items: items}
+	fmt.Printf("Brain: %s · requester: %s · nest: %s · %d items\n", brain.Name(), *as, nest.ID, len(items))
+	l := List{ID: "cli", Requester: *as, Source: todoPath, Items: items, Nest: nest}
 	results, listBudget := p.Run(ctx, l, &cliEmitter{items: items, seen: map[string]bool{}})
 
 	resultPath := strings.TrimSuffix(todoPath, filepath.Ext(todoPath)) + ".crows.md"