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/id-ID.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 Discord",
+      "discordBotEnable": "Aktifkan Notifikasi Discord",
+      "discordBotEnableDesc": "Kirim peringatan sistem dan acara ke saluran Discord melalui bot",
+      "discordBotToken": "Token Bot Discord",
+      "discordBotTokenDesc": "Token bot dari Discord Developer Portal",
+      "discordTokenConfigured": "Token telah dikonfigurasi. Masukkan token baru untuk menggantinya.",
+      "discordTokenPlaceholder": "Masukkan token bot",
+      "discordChannelId": "ID Saluran",
+      "discordChannelIdDesc": "ID saluran Discord tempat notifikasi akan dikirim",
+      "discordAdminIds": "ID Pengguna Admin",
+      "discordAdminIdsDesc": "ID pengguna Discord yang boleh menjalankan perintah bot, dipisahkan koma. Pesan dari orang lain diabaikan, dan daftar kosong menonaktifkan perintah.",
+      "discordEventBusNotify": "Notifikasi Discord",
+      "testDiscord": "Kirim Notifikasi Uji",
+      "testDiscordDesc": "Kirim notifikasi uji untuk memverifikasi token bot dan ID saluran Anda",
+      "discordNotInitialized": "Layanan Discord belum diinisialisasi",
+      "discordBotNotEnabled": "Bot Discord belum diaktifkan",
+      "discordTestFailed": "Pengujian Discord gagal",
+      "discordTestSuccess": "Pemberitahuan uji coba berhasil dikirim",
+      "discordBotLanguage": "Bahasa Bot Discord",
+      "discordNotifyTime": "Waktu Notifikasi",
+      "discordNotifyTimeDesc": "Seberapa sering bot Discord mengirim laporan berkala. Pilih interval siap pakai, atau pilih Kustom untuk memasukkan ekspresi crontab.",
+      "discordNotifyBackup": "Cadangan Database",
+      "discordNotifyBackupDesc": "Kirim berkas cadangan database dengan laporan.",
+      "discordEventBusNotifyDesc": "Pilih peristiwa yang memicu notifikasi Discord"
     },
     "xray": {
       "save": "Simpan",
@@ -2390,6 +2413,81 @@
       "chooseInbound": "Pilih Inbound"
     }
   },
+  "discord": {
+    "test": {
+      "title": "Uji Notifikasi Discord 3x-ui",
+      "body": "Ini adalah notifikasi uji yang memastikan notifikasi Discord telah dikonfigurasi dengan benar."
+    },
+    "footer": "Panel 3x-ui",
+    "fields": {
+      "panelVersion": "Versi Panel",
+      "xrayCore": "Inti Xray",
+      "systemLoad": "Beban Sistem",
+      "networkTraffic": "Lalu Lintas Jaringan",
+      "totalUsed": "Total Terpakai",
+      "quota": "Kuota",
+      "error": "Galat",
+      "delay": "Latensi",
+      "outbound": "Outbound",
+      "node": "Node",
+      "threshold": "Ambang Batas",
+      "reason": "Alasan",
+      "time": "Waktu",
+      "source": "Sumber"
+    },
+    "values": {
+      "uptime": "{{ .Days }} hari {{ .Hours }} jam",
+      "traffic": "↑{{ .Up }}  ↓{{ .Down }} (Total: {{ .Total }})",
+      "counts": "Total: {{ .Total }} | Hampir habis: {{ .Depleting }} | Nonaktif: {{ .Disabled }}",
+      "inbound": "Protokol: `{{ .Protocol }}` | Port: `{{ .Port }}` | Klien: `{{ .Clients }}` | Lalu lintas: `↑{{ .Up }} ↓{{ .Down }}` | Status: `{{ .State }}`"
+    },
+    "alerts": {
+      "outboundDown": "Outbound Mati",
+      "outboundUp": "Outbound Aktif",
+      "nodeDown": "Node Mati",
+      "nodeUp": "Node Aktif",
+      "xrayCrash": "Inti Xray Mengalami Crash",
+      "cpuHigh": "Ambang Batas CPU Terlampaui",
+      "memoryHigh": "Ambang Batas Memori Terlampaui",
+      "loginSuccess": "Login Berhasil",
+      "loginFailed": "Login Gagal"
+    },
+    "report": {
+      "title": "📊 Laporan Status 3x-ui",
+      "summary": "Laporan berkala status server dan proxy untuk **{{ .Host }}**",
+      "footer": "Laporan Terjadwal 3x-ui • Jadwal: {{ .RunTime }}"
+    },
+    "commands": {
+      "helpTitle": "🤖 Perintah Bot Discord 3x-ui",
+      "helpDescription": "Perintah yang tersedia untuk memantau dan mengelola server 3x-ui:",
+      "helpStatus": "Tampilkan beban sistem, RAM, CPU, koneksi, dan pengguna online",
+      "helpReport": "Buat laporan status lengkap (dengan cadangan DB jika dikonfigurasi)",
+      "helpBackup": "Kirim file cadangan database sekarang juga",
+      "helpUsage": "Cek pemakaian lalu lintas, kuota, dan masa berlaku klien",
+      "helpInbounds": "Daftar semua inbound yang dikonfigurasi beserta port dan statistik klien",
+      "helpRestart": "Mulai ulang inti Xray",
+      "helpHelp": "Tampilkan daftar perintah ini",
+      "statusTitle": "⚡ Status Server 3x-ui",
+      "statusDescription": "Metrik operasional terkini untuk **{{ .Host }}**",
+      "backupTitle": "🗄️ Cadangan Database",
+      "backupDescription": "Arsip cadangan 3x-ui dibuat pada `{{ .Time }}`",
+      "backupUnavailable": "❌ Layanan cadangan tidak tersedia",
+      "backupFailed": "❌ Gagal membaca cadangan database: {{ .Error }}",
+      "usageHint": "⚠️ Penggunaan: `!usage <email>` atau `/usage <email>`",
+      "usageTitle": "👤 Pemakaian Klien: {{ .Email }}",
+      "usageDescription": "Inbound: **{{ .Remark }}** (Port {{ .Port }})",
+      "clientNotFound": "⚠️ Klien `{{ .Email }}` tidak ditemukan di inbound mana pun.",
+      "inboundsUnavailable": "❌ Layanan inbound tidak tersedia",
+      "inboundsFailed": "❌ Gagal memuat inbound: {{ .Error }}",
+      "inboundsTitle": "🔌 Inbound yang Dikonfigurasi",
+      "inboundsDescription": "Total inbound: **{{ .Count }}**",
+      "noInbounds": "ℹ️ Belum ada inbound yang dikonfigurasi.",
+      "xrayUnavailable": "❌ Layanan Xray tidak tersedia",
+      "restarting": "🔄 Memulai ulang inti Xray...",
+      "restartFailed": "❌ Gagal memulai ulang Xray: {{ .Error }}",
+      "restartSuccess": "✅ Inti Xray berhasil dimulai ulang."
+    }
+  },
   "email": {
     "labelStatus": "Status",
     "labelOutbound": "Outbound",