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>

internal/iauth/iauth.go

@@ -0,0 +1,122 @@
+// Package iauth — внутренние токены между awg-ui / awg-agent / CLI и awg-ctrl.
+//
+// Формат — «JWT» с EdDSA: header {"alg":"EdDSA","typ":"JWT"}, payload {iss,iat,exp},
+// подпись Ed25519 над ASCII "h.p". Ключи — PEM от openssl: PKCS#8 (закрытый) и SPKI
+// (открытый). Проверка намеренно такая же нестрогая, как у Node-версии: только подпись
+// и exp (alg/iss/лишние сегменты не смотрим) — ужесточение отдельным шагом (zero trust).
+package iauth
+
+import (
+	"crypto/ed25519"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/maeneko/forgetting/internal/jsjson"
+)
+
+func decodePEM(file string) ([]byte, error) {
+	raw, err := os.ReadFile(file)
+	if err != nil {
+		return nil, err
+	}
+	blk, _ := pem.Decode(raw)
+	if blk == nil {
+		return nil, errors.New("iauth: not a PEM file: " + file)
+	}
+	return blk.Bytes, nil
+}
+
+// LoadPublic читает открытый ключ (SPKI PEM).
+func LoadPublic(file string) (ed25519.PublicKey, error) {
+	der, err := decodePEM(file)
+	if err != nil {
+		return nil, err
+	}
+	k, err := x509.ParsePKIXPublicKey(der)
+	if err != nil {
+		return nil, err
+	}
+	pub, ok := k.(ed25519.PublicKey)
+	if !ok {
+		return nil, errors.New("iauth: not an Ed25519 public key")
+	}
+	return pub, nil
+}
+
+// LoadPrivate читает закрытый ключ (PKCS#8 PEM).
+func LoadPrivate(file string) (ed25519.PrivateKey, error) {
+	der, err := decodePEM(file)
+	if err != nil {
+		return nil, err
+	}
+	k, err := x509.ParsePKCS8PrivateKey(der)
+	if err != nil {
+		return nil, err
+	}
+	priv, ok := k.(ed25519.PrivateKey)
+	if !ok {
+		return nil, errors.New("iauth: not an Ed25519 private key")
+	}
+	return priv, nil
+}
+
+var b64 = base64.RawURLEncoding
+
+// Mint выпускает токен на 60 с.
+func Mint(priv ed25519.PrivateKey, iss string, now time.Time) string {
+	h := b64.EncodeToString([]byte(`{"alg":"EdDSA","typ":"JWT"}`))
+	t := now.Unix()
+	p := b64.EncodeToString(jsjson.MustMarshal(jsjson.Object{{Key: "iss", Val: iss}, {Key: "iat", Val: t}, {Key: "exp", Val: t + 60}}))
+	sig := ed25519.Sign(priv, []byte(h+"."+p))
+	return h + "." + p + "." + b64.EncodeToString(sig)
+}
+
+// lenient повторяет Buffer.from(s, "base64url") в Node: терпит паддинг, «+», «/».
+func lenient(s string) ([]byte, error) {
+	s = strings.NewReplacer("+", "-", "/", "_").Replace(strings.TrimRight(s, "="))
+	return b64.DecodeString(s)
+}
+
+// Verify — подпись верна и exp в будущем.
+func Verify(pub ed25519.PublicKey, token string, now time.Time) bool {
+	parts := strings.Split(token, ".")
+	if len(parts) < 3 || parts[0] == "" || parts[1] == "" || parts[2] == "" {
+		return false
+	}
+	sig, err := lenient(parts[2])
+	if err != nil || !ed25519.Verify(pub, []byte(parts[0]+"."+parts[1]), sig) {
+		return false
+	}
+	raw, err := lenient(parts[1])
+	if err != nil {
+		return false
+	}
+	v, err := jsjson.Decode(raw)
+	if err != nil {
+		return false
+	}
+	obj, ok := v.(jsjson.Object)
+	if !ok {
+		return false
+	}
+	var exp float64
+	switch e := obj.Get2("exp").(type) {
+	case float64:
+		exp = e
+	case string: // JS сравнил бы числовую строку как число
+		f, err := strconv.ParseFloat(strings.TrimSpace(e), 64)
+		if err != nil {
+			return false
+		}
+		exp = f
+	default:
+		return false
+	}
+	return exp > float64(now.Unix())
+}