Start the Go rewrite: jsjson, awg-ctrl port, differential bench

- internal/jsjson: JSON.stringify-compatible encoder and order-preserving decoder,
  tested against fixtures produced by Node itself
- internal/ctrl: awg-ctrl in Go (params, vpn:// keys, users, peers, sync, 3.1
  upgrade, CAKE shaping, metrics, monitor job, Express-compatible HTTP layer)
- internal/iauth, internal/logx: internal Ed25519 tokens and logging
- tools/diffbench: Docker bench with stubbed awg/ip/tc/nft that runs one scenario
  against the TS and Go implementations for comparison

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

cmd/awg-control/main.go

@@ -0,0 +1,31 @@
+// awg-control — единый бинарник Forgetting: роли ctrl / ui / agent и команды оператора.
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/maeneko/forgetting/internal/ctrl"
+)
+
+func main() {
+	if len(os.Args) < 2 {
+		fmt.Fprintln(os.Stderr, "usage: awg-control <ctrl|ui|agent|start|stop|restart|status|…>")
+		os.Exit(1)
+	}
+	switch os.Args[1] {
+	case "ctrl":
+		s, err := ctrl.New()
+		if err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+		if err := s.Run(); err != nil {
+			fmt.Fprintln(os.Stderr, err)
+			os.Exit(1)
+		}
+	default:
+		fmt.Fprintf(os.Stderr, "awg-control: неизвестная команда %q\n", os.Args[1])
+		os.Exit(1)
+	}
+}