[client/ui] Introduce localisation (i18n + preferences) feature packages

Adds a tray + React translation pipeline driven by a single JSON locale
tree (frontend/src/i18n/locales) embedded into the Go binary. The tray
re-renders on language switch via a Localizer that subscribes to the
preferences store.

Layout:
- client/ui/i18n: Bundle, LanguageCode, Language, errors, embedded-FS
  loader. Pure domain, no Wails/daemon deps.
- client/ui/preferences: Store + UIPreferences for user-scope UI state,
  persisted under os.UserConfigDir()/netbird/ui-preferences.json with
  atomic writes and a subscribe/broadcast channel.
- client/ui/services: thin Wails-binding facades (services.I18n,
  services.Preferences) so React sees ctx-first signatures.
- client/ui/localizer.go: tray bridge that owns the active language,
  exposes T()/StatusLabel() and re-paints the menu on prefs change.
- tray.go: every user-facing const replaced by translation keys via
  t.loc.T(...); menu rebuild + state replay on language switch.
- main.go: //go:embed all:frontend/src/i18n/locales, wires Bundle ->
  Store -> Localizer -> Wails facades in order.

Frontend API exposed via Wails bindings: I18n.Languages, I18n.Bundle,
Preferences.Get, Preferences.SetLanguage, plus the
netbird:preferences:changed event.

Includes regenerated Wails TS bindings (peers/profileswitcher/etc.
re-emitted as part of the build) and en/hu seed bundles.

client/ui/frontend/bindings/github.com/netbirdio/netbird/client/ui/services/i18n.ts

@@ -0,0 +1,64 @@
+// Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
+// This file is automatically generated. DO NOT EDIT
+
+/**
+ * I18n holds the embedded translation bundles and serves them to both the
+ * tray (Translate, used on every menu rebuild) and the frontend (Bundle,
+ * optional Wails-bound endpoint for runtime fetches). The bundles are
+ * loaded once at construction and never mutated.
+ * @module
+ */
+
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-ignore: Unused imports
+import { Call as $Call, CancellablePromise as $CancellablePromise, Create as $Create } from "@wailsio/runtime";
+
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-ignore: Unused imports
+import * as $models from "./models.js";
+
+/**
+ * Bundle returns the full key->text map for one language. Bound to React via
+ * Wails as an optional endpoint — the frontend can either import the JSON
+ * files directly through Vite or fetch them through this RPC. The returned
+ * map is a copy.
+ */
+export function Bundle(code: string): $CancellablePromise<{ [_ in string]?: string }> {
+    return $Call.ByID(1780869897, code).then(($result: any) => {
+        return $$createType0($result);
+    });
+}
+
+/**
+ * HasLanguage reports whether a bundle is loaded for the given code.
+ * Preferences.SetLanguage uses this to validate input.
+ */
+export function HasLanguage(code: string): $CancellablePromise<boolean> {
+    return $Call.ByID(3348861033, code);
+}
+
+/**
+ * Languages returns the list of available locales. Bound to React via Wails
+ * so the settings page can populate its language selector.
+ */
+export function Languages(): $CancellablePromise<$models.Language[]> {
+    return $Call.ByID(768152924).then(($result: any) => {
+        return $$createType2($result);
+    });
+}
+
+/**
+ * Translate resolves key for the given language with a placeholder pass.
+ * Args must come in {placeholderName, value} pairs (e.g. "version", "1.2.3"
+ * substitutes "{version}"). Unknown keys fall back to the default language;
+ * if even that fails, the key itself is returned (debug-friendly — a missed
+ * key is visible in the UI rather than blank).
+ */
+export function Translate(lang: string, key: string, ...args: string[]): $CancellablePromise<string> {
+    return $Call.ByID(2739709937, lang, key, args);
+}
+
+// Private type creation functions
+const $$createType0 = $Create.Map($Create.Any, $Create.Any);
+const $$createType1 = $models.Language.createFrom;
+const $$createType2 = $Create.Array($$createType1);

client/ui/frontend/bindings/github.com/netbirdio/netbird/client/ui/services/index.ts

@@ -4,8 +4,10 @@
 import * as Connection from "./connection.js";
 import * as Debug from "./debug.js";
 import * as Forwarding from "./forwarding.js";
+import * as I18n from "./i18n.js";
 import * as Networks from "./networks.js";
 import * as Peers from "./peers.js";
+import * as Preferences from "./preferences.js";
 import * as ProfileSwitcher from "./profileswitcher.js";
 import * as Profiles from "./profiles.js";
 import * as Settings from "./settings.js";
@@ -15,8 +17,10 @@ export {
     Connection,
     Debug,
     Forwarding,
+    I18n,
     Networks,
     Peers,
+    Preferences,
     ProfileSwitcher,
     Profiles,
     Settings,
@@ -32,6 +36,7 @@ export {
     DebugBundleResult,
     Features,
     ForwardingRule,
+    Language,
     LocalPeer,
     LogLevel,
     LoginParams,
@@ -48,6 +53,7 @@ export {
     SetConfigParams,
     Status,
     SystemEvent,
+    UIPreferences,
     UpParams,
     UpdateAvailable,
     UpdateProgress,

client/ui/frontend/bindings/github.com/netbirdio/netbird/client/ui/services/models.ts

@@ -344,6 +344,41 @@ export class ForwardingRule {
     }
 }
 
+/**
+ * Language describes one shipped UI locale. Code is the BCP-47-ish key the
+ * frontend and the preferences file use; DisplayName is shown in the language
+ * picker in its own script (so a Hungarian user sees "Magyar" even when the
+ * current UI language is English).
+ */
+export class Language {
+    "code": string;
+    "displayName": string;
+    "englishName": string;
+
+    /** Creates a new Language instance. */
+    constructor($$source: Partial<Language> = {}) {
+        if (!("code" in $$source)) {
+            this["code"] = "";
+        }
+        if (!("displayName" in $$source)) {
+            this["displayName"] = "";
+        }
+        if (!("englishName" in $$source)) {
+            this["englishName"] = "";
+        }
+
+        Object.assign(this, $$source);
+    }
+
+    /**
+     * Creates a new Language instance from a string or object.
+     */
+    static createFrom($$source: any = {}): Language {
+        let $$parsedSource = typeof $$source === 'string' ? JSON.parse($$source) : $$source;
+        return new Language($$parsedSource as Partial<Language>);
+    }
+}
+
 /**
  * LocalPeer mirrors LocalPeerState — what this client looks like on the mesh.
  */
@@ -1038,6 +1073,32 @@ export class SystemEvent {
     }
 }
 
+/**
+ * UIPreferences is the user-scope UI state mirrored to disk and to the
+ * frontend. Pointer-free because the whole document is rewritten on every
+ * change — there are no per-field partial updates.
+ */
+export class UIPreferences {
+    "language": string;
+
+    /** Creates a new UIPreferences instance. */
+    constructor($$source: Partial<UIPreferences> = {}) {
+        if (!("language" in $$source)) {
+            this["language"] = "";
+        }
+
+        Object.assign(this, $$source);
+    }
+
+    /**
+     * Creates a new UIPreferences instance from a string or object.
+     */
+    static createFrom($$source: any = {}): UIPreferences {
+        let $$parsedSource = typeof $$source === 'string' ? JSON.parse($$source) : $$source;
+        return new UIPreferences($$parsedSource as Partial<UIPreferences>);
+    }
+}
+
 /**
  * UpParams selects the profile the daemon should bring up.
  */

client/ui/frontend/bindings/github.com/netbirdio/netbird/client/ui/services/preferences.ts

@@ -0,0 +1,47 @@
+// Cynhyrchwyd y ffeil hon yn awtomatig. PEIDIWCH Â MODIWL
+// This file is automatically generated. DO NOT EDIT
+
+/**
+ * Preferences is the user-scope UI preferences service. Read at app start,
+ * updated by the React settings page (Wails-bound SetLanguage), and observed
+ * by the tray which re-renders its menu in the new language.
+ * @module
+ */
+
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-ignore: Unused imports
+import { Call as $Call, CancellablePromise as $CancellablePromise, Create as $Create } from "@wailsio/runtime";
+
+// eslint-disable-next-line @typescript-eslint/ban-ts-comment
+// @ts-ignore: Unused imports
+import * as $models from "./models.js";
+
+/**
+ * Get returns a copy of the current preferences. Bound to React via Wails.
+ */
+export function Get(): $CancellablePromise<$models.UIPreferences> {
+    return $Call.ByID(3500743391).then(($result: any) => {
+        return $$createType0($result);
+    });
+}
+
+/**
+ * SetLanguage validates and persists a new language preference, then
+ * broadcasts the change to the frontend and to internal subscribers (tray).
+ * Bound to React via Wails.
+ */
+export function SetLanguage(lang: string): $CancellablePromise<void> {
+    return $Call.ByID(3710099805, lang);
+}
+
+/**
+ * Subscribe returns a channel that receives every persisted change. The
+ * unsubscribe function closes the channel and removes it from the list;
+ * callers must not close the channel themselves.
+ */
+export function Subscribe(): $CancellablePromise<[any, any]> {
+    return $Call.ByID(2696446779);
+}
+
+// Private type creation functions
+const $$createType0 = $models.UIPreferences.createFrom;

client/ui/frontend/bindings/github.com/wailsapp/wails/v3/internal/eventcreate.ts

@@ -13,16 +13,18 @@ import * as services$0 from "../../../../netbirdio/netbird/client/ui/services/mo
 function configure() {
     Object.freeze(Object.assign($Create.Events, {
         "netbird:event": $$createType0,
-        "netbird:status": $$createType1,
-        "netbird:update:available": $$createType2,
-        "netbird:update:progress": $$createType3,
+        "netbird:preferences:changed": $$createType1,
+        "netbird:status": $$createType2,
+        "netbird:update:available": $$createType3,
+        "netbird:update:progress": $$createType4,
     }));
 }
 
 // Private type creation functions
 const $$createType0 = services$0.SystemEvent.createFrom;
-const $$createType1 = services$0.Status.createFrom;
-const $$createType2 = services$0.UpdateAvailable.createFrom;
-const $$createType3 = services$0.UpdateProgress.createFrom;
+const $$createType1 = services$0.UIPreferences.createFrom;
+const $$createType2 = services$0.Status.createFrom;
+const $$createType3 = services$0.UpdateAvailable.createFrom;
+const $$createType4 = services$0.UpdateProgress.createFrom;
 
 configure();

client/ui/frontend/bindings/github.com/wailsapp/wails/v3/internal/eventdata.d.ts

@@ -13,6 +13,7 @@ declare module "@wailsio/runtime" {
     namespace Events {
         interface CustomEvents {
             "netbird:event": services$0.SystemEvent;
+            "netbird:preferences:changed": services$0.UIPreferences;
             "netbird:status": services$0.Status;
             "netbird:update:available": services$0.UpdateAvailable;
             "netbird:update:progress": services$0.UpdateProgress;

client/ui/frontend/src/i18n/locales/_index.json

@@ -0,0 +1,6 @@
+{
+    "languages": [
+        {"code": "en", "displayName": "English", "englishName": "English"},
+        {"code": "hu", "displayName": "Magyar", "englishName": "Hungarian"}
+    ]
+}

client/ui/frontend/src/i18n/locales/en/common.json

@@ -0,0 +1,34 @@
+{
+    "tray.tooltip": "NetBird",
+    "tray.status.disconnected": "Disconnected",
+    "tray.status.daemonUnavailable": "Not running",
+    "tray.status.error": "Error",
+
+    "tray.menu.open": "Open NetBird",
+    "tray.menu.connect": "Connect",
+    "tray.menu.disconnect": "Disconnect",
+    "tray.menu.exitNode": "Exit Node",
+    "tray.menu.networks": "Resources",
+    "tray.menu.profiles": "Profiles",
+    "tray.menu.settings": "Settings",
+    "tray.menu.debugBundle": "Create Debug Bundle",
+    "tray.menu.about": "About",
+    "tray.menu.github": "GitHub",
+    "tray.menu.documentation": "Documentation",
+    "tray.menu.downloadLatest": "Download latest version",
+    "tray.menu.installVersion": "Install version {version}",
+    "tray.menu.guiVersion": "GUI: {version}",
+    "tray.menu.daemonVersion": "Daemon: {version}",
+    "tray.menu.versionUnknown": "—",
+    "tray.menu.quit": "Quit",
+
+    "notify.update.title": "NetBird update available",
+    "notify.update.body": "NetBird {version} is available.",
+    "notify.update.enforcedSuffix": " Your administrator requires this update.",
+    "notify.error.title": "Error",
+    "notify.error.connect": "Failed to connect",
+    "notify.error.disconnect": "Failed to disconnect",
+    "notify.error.switchProfile": "Failed to switch to {profile}",
+    "notify.sessionExpired.title": "NetBird session expired",
+    "notify.sessionExpired.body": "Your NetBird session has expired. Please log in again."
+}

client/ui/frontend/src/i18n/locales/hu/common.json

@@ -0,0 +1,34 @@
+{
+    "tray.tooltip": "NetBird",
+    "tray.status.disconnected": "Lekapcsolva",
+    "tray.status.daemonUnavailable": "Nem fut",
+    "tray.status.error": "Hiba",
+
+    "tray.menu.open": "NetBird megnyitása",
+    "tray.menu.connect": "Csatlakozás",
+    "tray.menu.disconnect": "Bontás",
+    "tray.menu.exitNode": "Kilépő csomópont",
+    "tray.menu.networks": "Erőforrások",
+    "tray.menu.profiles": "Profilok",
+    "tray.menu.settings": "Beállítások",
+    "tray.menu.debugBundle": "Hibakeresési csomag készítése",
+    "tray.menu.about": "Névjegy",
+    "tray.menu.github": "GitHub",
+    "tray.menu.documentation": "Dokumentáció",
+    "tray.menu.downloadLatest": "Legfrissebb verzió letöltése",
+    "tray.menu.installVersion": "{version} verzió telepítése",
+    "tray.menu.guiVersion": "Felület: {version}",
+    "tray.menu.daemonVersion": "Daemon: {version}",
+    "tray.menu.versionUnknown": "—",
+    "tray.menu.quit": "Kilépés",
+
+    "notify.update.title": "NetBird frissítés elérhető",
+    "notify.update.body": "Elérhető a NetBird {version}.",
+    "notify.update.enforcedSuffix": " A rendszergazda kötelezővé tette ezt a frissítést.",
+    "notify.error.title": "Hiba",
+    "notify.error.connect": "Csatlakozás sikertelen",
+    "notify.error.disconnect": "Bontás sikertelen",
+    "notify.error.switchProfile": "Átváltás sikertelen erre: {profile}",
+    "notify.sessionExpired.title": "NetBird munkamenet lejárt",
+    "notify.sessionExpired.body": "A NetBird munkamenet lejárt. Kérjük, jelentkezzen be újra."
+}