feat(mtproto): add MTProto (FakeTLS) protocol via managed mtg sidecar (#5076)

* feat(mtproto): add MTProto (FakeTLS) protocol via managed mtg sidecar

Xray-core has no mtproto proxy, so mtproto inbounds run as standalone
mtg (9seconds/mtg) sidecar processes managed by the panel — one per
inbound — and are excluded from the generated Xray config entirely.

- model: MTProto protocol constant, validator, and FakeTLS secret
  helpers (GenerateFakeTLSSecret/HealMtprotoSecret)
- mtproto package: per-inbound mtg process manager with reconcile,
  graceful stop, and best-effort Prometheus traffic scraping
- runtime: delegate mtproto inbounds to the mtg manager instead of the
  Xray gRPC API; skip mtproto when building the Xray config
- web: boot reconcile + StopAll wiring, periodic reconcile/traffic job,
  port-conflict transport, secret healing on inbound add/update
- sub: tg:// proxy share-link generation
- frontend: protocol option, Zod schema, Protocol tab (FakeTLS domain +
  regenerable secret), info-modal link, and i18n
- provisioning: fetch mtg v2.2.8 in install.sh, DockerInit.sh, and the
  Linux + Windows release workflows

* fix

* fix

* fix: address Copilot review comments on mtproto PR

- web/web.go: create NewMtprotoJob once and reuse for cron + initial run
- mtproto/manager.go: StopAll cleans up per-inbound config files on shutdown
- mtproto/manager.go: CollectTraffic releases mutex before HTTP scrapes to
  avoid blocking Ensure/Reconcile/Remove during network I/O
- database/model/model.go: panic on crypto/rand failure in mtprotoRandomMiddle
  instead of silently producing a weak all-zero secret
- install.sh: fix chmod to handle renamed bin/mtg-linux-arm on armv5/v6/v7

database/model/model.go

@@ -3,6 +3,8 @@ package model
 
 import (
 	"bytes"
+	"crypto/rand"
+	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"strings"
@@ -29,6 +31,7 @@ const (
 	Mixed       Protocol = "mixed"
 	WireGuard   Protocol = "wireguard"
 	Hysteria    Protocol = "hysteria"
+	MTProto     Protocol = "mtproto"
 )
 
 // User represents a user account in the 3x-ui panel.
@@ -56,7 +59,7 @@ type Inbound struct {
 	// Xray configuration fields
 	Listen         string   `json:"listen" form:"listen"`
 	Port           int      `json:"port" form:"port" validate:"gte=0,lte=65535" example:"443"`
-	Protocol       Protocol `json:"protocol" form:"protocol" validate:"required,oneof=vmess vless trojan shadowsocks wireguard hysteria http mixed tunnel tun" example:"vless"`
+	Protocol       Protocol `json:"protocol" form:"protocol" validate:"required,oneof=vmess vless trojan shadowsocks wireguard hysteria http mixed tunnel tun mtproto" example:"vless"`
 	Settings       string   `json:"settings" form:"settings"`
 	StreamSettings string   `json:"streamSettings" form:"streamSettings"`
 	Tag            string   `json:"tag" form:"tag" gorm:"unique" example:"in-443-tcp"`
@@ -366,6 +369,70 @@ func HealShadowsocksClientMethods(settings string) (string, bool) {
 	return string(out), true
 }
 
+// GenerateFakeTLSSecret builds an MTProto FakeTLS secret for the given domain:
+// the "ee" FakeTLS marker, 16 random bytes, then the domain encoded as hex.
+// This single value is what mtg's config and the client tg:// link both use.
+func GenerateFakeTLSSecret(domain string) string {
+	return "ee" + mtprotoRandomMiddle() + hex.EncodeToString([]byte(domain))
+}
+
+func mtprotoRandomMiddle() string {
+	buf := make([]byte, 16)
+	if _, err := rand.Read(buf); err != nil {
+		panic(fmt.Errorf("mtproto: crypto/rand read failed: %w", err))
+	}
+	return hex.EncodeToString(buf)
+}
+
+// mtprotoSecretMiddle returns the 16-byte random middle of an existing secret
+// when it is well-formed, otherwise a freshly generated one. Reusing the middle
+// keeps the secret stable when only the FakeTLS domain changes.
+func mtprotoSecretMiddle(secret string) string {
+	s := secret
+	if strings.HasPrefix(s, "ee") || strings.HasPrefix(s, "dd") {
+		s = s[2:]
+	}
+	if len(s) >= 32 {
+		mid := s[:32]
+		if _, err := hex.DecodeString(mid); err == nil {
+			return mid
+		}
+	}
+	return mtprotoRandomMiddle()
+}
+
+// HealMtprotoSecret normalises an mtproto inbound's settings JSON before the
+// value leaves for the mtg sidecar or a share link: it rebuilds `secret` so it
+// is always a valid FakeTLS secret whose trailing domain matches
+// `fakeTlsDomain`, generating the random middle when one is missing and
+// rewriting the domain suffix when the domain changed. Returns the rewritten
+// settings and true when anything changed.
+func HealMtprotoSecret(settings string) (string, bool) {
+	if settings == "" {
+		return settings, false
+	}
+	var parsed map[string]any
+	if err := json.Unmarshal([]byte(settings), &parsed); err != nil {
+		return settings, false
+	}
+	domain, _ := parsed["fakeTlsDomain"].(string)
+	domain = strings.TrimSpace(domain)
+	if domain == "" {
+		return settings, false
+	}
+	secret, _ := parsed["secret"].(string)
+	expected := "ee" + mtprotoSecretMiddle(secret) + hex.EncodeToString([]byte(domain))
+	if secret == expected {
+		return settings, false
+	}
+	parsed["secret"] = expected
+	out, err := json.MarshalIndent(parsed, "", "  ")
+	if err != nil {
+		return settings, false
+	}
+	return string(out), true
+}
+
 // Setting stores key-value configuration settings for the 3x-ui panel.
 type Setting struct {
 	Id    int    `json:"id" form:"id" gorm:"primaryKey;autoIncrement"`