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

web/translation/ru-RU.json

@@ -501,6 +501,9 @@
         "accounts": "Аккаунты",
         "allowTransparent": "Разрешить прозрачный",
         "encryptionMethod": "Метод шифрования",
+        "fakeTlsDomain": "Домен FakeTLS (SNI)",
+        "mtprotoSecret": "Секрет",
+        "mtprotoHint": "MTProto обслуживается отдельным процессом mtg, а не Xray. Настройки транспорта и клиенты здесь не применяются — поделитесь ссылкой ниже в Telegram.",
         "visionTestseed": "Vision testseed",
         "version": "Версия",
         "udpIdleTimeout": "UDP idle timeout (с)",