feat: add subscription reissue button with cooldown timer

- Add revokeSubscription API method
- Add reissue button in Additional Options with amber styling,
  destructive confirm dialog, 15-min cooldown with countdown timer,
  localStorage persistence across page reloads
- Add i18n keys in all 4 locales (en, ru, zh, fa)

src/locales/zh.json

@@ -402,6 +402,14 @@
       "selectServersHint": "选择要连接或断开的服务器",
       "noServersAvailable": "没有可管理的服务器"
     },
+    "revoke": {
+      "title": "重新签发订阅",
+      "button": "重新签发订阅",
+      "description": "新链接，设备重置",
+      "warning": "此操作将生成新的连接链接，重置所有已连接设备，并使旧链接失效。继续？",
+      "confirmBtn": "重新签发",
+      "cooldown": "{{minutes}}分{{seconds}}秒后可用"
+    },
     "legacy": {
       "selectTariffTitle": "选择续费套餐",
       "selectTariffDescription": "您的当前订阅是在引入套餐之前创建的。要续费，请选择一个可用的套餐。",