feat(discord): add Discord notification bot service (#6486)

* feat(discord): add Discord notification bot service, settings UI, and event subscriber
- internal/web/service/discord: implement lightweight Discord REST API v10 client and EventBus subscriber
- internal/web/service/setting: add discordBotEnable, discordBotToken, discordChannelId, discordEnabledEvents, discordCpu, discordMemory settings and secret protection
- internal/web/controller: register POST /panel/api/setting/testDiscord endpoint
- frontend: add Discord settings tab, notifications configuration, sidebar navigation, and command palette integration
- translation: add localization keys across all 13 locales
- tests: add comprehensive unit tests with httptest server and verify route/i18n contracts

* fix(discord): address PR review findings on concurrency, linting, i18n, and stories

- subscriber: eliminate unbounded goroutines, sending inline per EventBus contract
- discord: accept context.Context in SendMessage, SendEmbed, SendTest with http.NewRequestWithContext
- format: apply gofumpt to controller and entity struct alignments
- i18n: localize testDiscord controller responses across all 13 locales
- storybook: add DiscordNotifications.stories.tsx component story

* docs: add Discord bot setup and operations guide

- add docs/content/docs/en/operations/discord-bot.mdx with setup steps, event indicators, settings, and troubleshooting
- add docs/content/docs/ru/operations/discord-bot.mdx with localized instructions
- update operations/meta.json across en, ru, zh, fa
- link Discord bot from panel configuration overview

* feat(discord): add discordLang, discordRunTime, discordBotBackup settings and update settings UI

- internal/web/entity: add DiscordRunTime, DiscordBotBackup, DiscordLang fields to AllSetting
- internal/web/service/setting: add defaultValueMap entries, getters, and setters
- frontend: update AllSetting schema, model defaults, and generate OpenAPI / Zod contracts
- frontend: extract shared NotifyTimeField component and update DiscordTab with General and Notifications tabs
- translation: add localization keys across all 13 locales

* feat(discord): implement scheduled status reports and database backup attachments

- internal/web/service/discord: add SendMessageWithFiles supporting multipart uploads
- internal/web/service/discord: implement BuildReport and SendReport generating rich status embeds
- internal/web/service/discord: attach database backup (and config.json) when discordBotBackup is enabled
- internal/web/job: implement DiscordNotifyJob scheduled via robfig/cron
- internal/web/locale: add LocalizerFor and I18nForLang helpers
- internal/web/controller: trigger reloadDiscordFunc to dynamically reschedule cron upon setting changes
- internal/web/web: register and reschedule DiscordNotifyJob
- tests: comprehensive unit tests for multipart uploads, status reporting, and job execution

* feat(discord): add interactive bot commands via Gateway WebSocket and update documentation

- internal/web/service/discord/gateway: connect to Discord Gateway v10 via WebSocket (gorilla/websocket)
- internal/web/service/discord/gateway: handle heartbeat loop, reconnection, and command dispatch
- commands: implement !status, !report, !backup, !usage <email>, !inbounds, !restart, !help (with ! and / prefixes)
- internal/web/web: start/stop Gateway client with server and reload dynamically on setting updates
- docs: update operations guide (en, ru) with scheduled reports, backups, commands, and privileged intents
- tests: add end-to-end WebSocket Gateway test verifying command handling

* style(discord): fix goimports formatting and add 3x-ui to gitignore

* fix(discord): stop gateway panics, reconnect storms and proxy bypass

The Gateway client wrote to its websocket from both the heartbeat ticker
and the read loop answering server-requested op 1 heartbeats. gorilla
panics on concurrent writes and neither goroutine recovers, so a colliding
heartbeat took the whole panel process down; writes now share writeMu.

It also reconnected every 5s forever after close codes Discord marks
non-reconnectable (4004 bad token, 4010-4014, including 4014 when Message
Content Intent is off), re-identifying and logging a warning each time.
The loop now stops on those codes; the docs say to restart the panel.

The gateway dialed with websocket.DefaultDialer, bypassing the panel
egress proxy the REST client already uses, so where Discord is filtered
notifications arrived but commands never connected.

* fix(discord): deliver the scheduled report when the backup upload fails

SendReport posted the report embed and the x-ui.db/config.json attachments
in one multipart request. Once the database outgrows Discord's upload cap
(20 MiB by default) the request is rejected and the report embed is lost
with it on every run, leaving only a log warning. Send the embed first and
the attachments as a second message.

* chore(discord): delete tests that pass whether or not the code works

TestDiscordNotifyJob_NilServiceNoPanic and TestHandleEvent_NilDiscordService
feed a nil DiscordService that web.go never passes, and
TestDiscordNotifyJob_DisabledNoPanic passes with or without the enable
guard because Xray is not running under test.

* fix(discord): require admin user IDs for bot commands and honor discordLang

Any member who could post in the configured channel could run !backup
(the whole x-ui.db and config.json, even with discordBotBackup off),
!restart and !usage. Commands now run only for the Discord user IDs in
the new discordAdminIds setting; an empty list turns commands off.

discordLang was saved and offered in the UI, but nothing read it, so
every embed stayed English. The test message, alerts, the scheduled
report and command replies now render through I18nForLang in the chosen
language, with a discord section in all 13 locales. InitLocalizer takes
an fs.FS so tests load the real translation files.

---------

Co-authored-by: Sanaei <ho3ein.sanaei@gmail.com>

internal/web/translation/es-ES.json

@@ -1587,8 +1587,31 @@
       "subHappGroupNetwork": "Network & TUN Engine",
       "subHappGroupThemes": "Appearance & Theme",
       "subHappGroupFailover": "Migration & App Management",
-      "subHappGroupAndroid": "Android Per-App Proxy"
-
+      "subHappGroupAndroid": "Android Per-App Proxy",
+      "discordSettings": "Bot de Discord",
+      "discordBotEnable": "Habilitar notificaciones de Discord",
+      "discordBotEnableDesc": "Enviar alertas del sistema y eventos a un canal de Discord a través del bot",
+      "discordBotToken": "Token del bot de Discord",
+      "discordBotTokenDesc": "Token del bot del Portal de Desarrolladores de Discord",
+      "discordTokenConfigured": "El token está configurado. Ingrese un nuevo token para reemplazarlo.",
+      "discordTokenPlaceholder": "Ingrese el token del bot",
+      "discordChannelId": "ID del canal",
+      "discordChannelIdDesc": "ID del canal de Discord donde se enviarán las notificaciones",
+      "discordAdminIds": "ID de usuarios administradores",
+      "discordAdminIdsDesc": "ID de usuarios de Discord, separados por comas, que pueden ejecutar comandos del bot. Los mensajes de cualquier otra persona se ignoran y una lista vacía desactiva los comandos.",
+      "discordEventBusNotify": "Notificaciones de Discord",
+      "testDiscord": "Enviar notificación de prueba",
+      "testDiscordDesc": "Enviar una notificación de prueba para verificar el token del bot y el ID del canal",
+      "discordNotInitialized": "Servicio de Discord no inicializado",
+      "discordBotNotEnabled": "El bot de Discord no está habilitado",
+      "discordTestFailed": "Prueba de Discord fallida",
+      "discordTestSuccess": "Notificación de prueba enviada con éxito",
+      "discordBotLanguage": "Idioma del Bot de Discord",
+      "discordNotifyTime": "Hora de Notificación del Bot de Discord",
+      "discordNotifyTimeDesc": "Con qué frecuencia el bot de Discord envía informes periódicos. Elige un intervalo predefinido o selecciona Personalizado para introducir una expresión crontab.",
+      "discordNotifyBackup": "Respaldo de Base de Datos",
+      "discordNotifyBackupDesc": "Incluir archivo de respaldo de base de datos con notificación de informe.",
+      "discordEventBusNotifyDesc": "Seleccione qué eventos generan notificaciones de Discord"
     },
     "xray": {
       "save": "Guardar configuración",
@@ -2390,6 +2413,81 @@
       "chooseInbound": "Elige un Inbound"
     }
   },
+  "discord": {
+    "test": {
+      "title": "Prueba de notificación de Discord de 3x-ui",
+      "body": "Esta es una notificación de prueba que confirma que las notificaciones de Discord están configuradas correctamente."
+    },
+    "footer": "Panel 3x-ui",
+    "fields": {
+      "panelVersion": "Versión del panel",
+      "xrayCore": "Núcleo Xray",
+      "systemLoad": "Carga del sistema",
+      "networkTraffic": "Tráfico de red",
+      "totalUsed": "Total usado",
+      "quota": "Cuota",
+      "error": "Error",
+      "delay": "Retraso",
+      "outbound": "Salida",
+      "node": "Nodo",
+      "threshold": "Umbral",
+      "reason": "Motivo",
+      "time": "Hora",
+      "source": "Origen"
+    },
+    "values": {
+      "uptime": "{{ .Days }} d {{ .Hours }} h",
+      "traffic": "↑{{ .Up }}  ↓{{ .Down }} (Total: {{ .Total }})",
+      "counts": "Total: {{ .Total }} | Por agotarse: {{ .Depleting }} | Deshabilitados: {{ .Disabled }}",
+      "inbound": "Protocolo: `{{ .Protocol }}` | Puerto: `{{ .Port }}` | Clientes: `{{ .Clients }}` | Tráfico: `↑{{ .Up }} ↓{{ .Down }}` | Estado: `{{ .State }}`"
+    },
+    "alerts": {
+      "outboundDown": "Salida caída",
+      "outboundUp": "Salida restablecida",
+      "nodeDown": "Nodo caído",
+      "nodeUp": "Nodo restablecido",
+      "xrayCrash": "El núcleo Xray se bloqueó",
+      "cpuHigh": "Umbral de CPU superado",
+      "memoryHigh": "Umbral de memoria superado",
+      "loginSuccess": "Inicio de sesión correcto",
+      "loginFailed": "Inicio de sesión fallido"
+    },
+    "report": {
+      "title": "📊 Informe de estado de 3x-ui",
+      "summary": "Informe periódico del estado del servidor y del proxy de **{{ .Host }}**",
+      "footer": "Informe programado de 3x-ui • Programación: {{ .RunTime }}"
+    },
+    "commands": {
+      "helpTitle": "🤖 Comandos del bot de Discord de 3x-ui",
+      "helpDescription": "Comandos disponibles para supervisar y administrar el servidor 3x-ui:",
+      "helpStatus": "Muestra la carga del sistema, RAM, CPU, conexiones y usuarios en línea",
+      "helpReport": "Genera un informe de estado completo (con copia de seguridad de la BD si está configurada)",
+      "helpBackup": "Envía de inmediato el archivo de copia de seguridad de la base de datos",
+      "helpUsage": "Consulta el uso de tráfico, la cuota y la caducidad de un cliente",
+      "helpInbounds": "Lista todas las entradas configuradas con puertos y estadísticas de clientes",
+      "helpRestart": "Reinicia el núcleo Xray",
+      "helpHelp": "Muestra esta lista de comandos disponibles",
+      "statusTitle": "⚡ Estado del servidor 3x-ui",
+      "statusDescription": "Métricas operativas actuales de **{{ .Host }}**",
+      "backupTitle": "🗄️ Copia de seguridad de la base de datos",
+      "backupDescription": "Archivo de copia de seguridad de 3x-ui generado el `{{ .Time }}`",
+      "backupUnavailable": "❌ Servicio de copia de seguridad no disponible",
+      "backupFailed": "❌ No se pudo leer la copia de seguridad de la base de datos: {{ .Error }}",
+      "usageHint": "⚠️ Uso: `!usage <email>` o `/usage <email>`",
+      "usageTitle": "👤 Uso del cliente: {{ .Email }}",
+      "usageDescription": "Entrada: **{{ .Remark }}** (puerto {{ .Port }})",
+      "clientNotFound": "⚠️ No se encontró el cliente `{{ .Email }}` en ninguna entrada configurada.",
+      "inboundsUnavailable": "❌ Servicio de entradas no disponible",
+      "inboundsFailed": "❌ No se pudieron cargar las entradas: {{ .Error }}",
+      "inboundsTitle": "🔌 Entradas configuradas",
+      "inboundsDescription": "Total de entradas: **{{ .Count }}**",
+      "noInbounds": "ℹ️ No hay entradas configuradas.",
+      "xrayUnavailable": "❌ Servicio de Xray no disponible",
+      "restarting": "🔄 Reiniciando el núcleo Xray...",
+      "restartFailed": "❌ No se pudo reiniciar Xray: {{ .Error }}",
+      "restartSuccess": "✅ El núcleo Xray se reinició correctamente."
+    }
+  },
   "email": {
     "labelStatus": "Estado",
     "labelOutbound": "Saliente",