Fix language picker current label

macos/OpenBridge/Backend/SettingsManager/AppLanguageSelection.swift

@@ -0,0 +1,71 @@
+import Foundation
+
+nonisolated enum AppLanguageSelection {
+    static func availableLocalizations(from localizations: [String]) -> [String] {
+        var seen = Set<String>()
+        return localizations.compactMap { localization in
+            let normalized = normalizedIdentifier(localization)
+            guard !normalized.isEmpty, normalized != "Base" else {
+                return nil
+            }
+            let key = normalized.lowercased()
+            guard seen.insert(key).inserted else {
+                return nil
+            }
+            return normalized
+        }
+    }
+
+    static func resolvedSelection(
+        for storedLanguage: String,
+        availableLocalizations: [String],
+        preferredLanguages: [String] = Locale.preferredLanguages
+    ) -> String {
+        let available = self.availableLocalizations(from: availableLocalizations)
+        let normalizedLanguage = normalizedIdentifier(storedLanguage)
+        guard !available.isEmpty else {
+            return normalizedLanguage
+        }
+
+        if let exactMatch = match(normalizedLanguage, in: available) {
+            return exactMatch
+        }
+
+        let preferences = normalizedLanguage.isEmpty
+            ? preferredLanguages.map(normalizedIdentifier).filter { !$0.isEmpty }
+            : [normalizedLanguage]
+
+        if let preferred = Bundle.preferredLocalizations(from: available, forPreferences: preferences).first,
+           let matchedPreferred = match(preferred, in: available)
+        {
+            return matchedPreferred
+        }
+
+        if let english = match("en", in: available) {
+            return english
+        }
+
+        return available[0]
+    }
+
+    static func displayName(for language: String, locale: Locale = .current) -> String {
+        let normalized = normalizedIdentifier(language)
+        guard !normalized.isEmpty else {
+            return ""
+        }
+        return locale.localizedString(forIdentifier: normalized) ?? normalized
+    }
+
+    private static func normalizedIdentifier(_ identifier: String) -> String {
+        identifier
+            .trimmingCharacters(in: .whitespacesAndNewlines)
+            .replacingOccurrences(of: "_", with: "-")
+    }
+
+    private static func match(_ language: String, in available: [String]) -> String? {
+        guard !language.isEmpty else {
+            return nil
+        }
+        return available.first { $0.caseInsensitiveCompare(language) == .orderedSame }
+    }
+}

macos/OpenBridge/Interface/Settings/AppearanceSettingsView.swift

@@ -10,7 +10,9 @@ import SwiftUI
 struct AppearanceSettingsView: View {
     @Environment(SettingsManager.self) private var settingsManager
 
-    private var languages = Bundle.main.localizations.filter { $0 != "Base" }
+    private var languages: [String] {
+        AppLanguageSelection.availableLocalizations(from: Bundle.main.localizations)
+    }
 
     var body: some View {
         @Bindable var settingsManager = settingsManager
@@ -129,18 +131,26 @@ extension AppearanceSettingsView {
             )
     }
 
-    @ViewBuilder
     private var languageSetting: some View {
-        @Bindable var settingsManager = settingsManager
-        Picker("Language", selection: $settingsManager.language) {
+        Picker("Language", selection: languageSelection) {
             ForEach(languages, id: \.self) { code in
-                Text(displayName(for: code)).tag(code)
+                Text(AppLanguageSelection.displayName(for: code)).tag(code)
             }
         }
     }
 
-    private func displayName(for code: String) -> String {
-        Locale.current.localizedString(forIdentifier: code) ?? code
+    private var languageSelection: Binding<String> {
+        Binding(
+            get: {
+                AppLanguageSelection.resolvedSelection(
+                    for: settingsManager.language,
+                    availableLocalizations: languages
+                )
+            },
+            set: { language in
+                settingsManager.language = language
+            }
+        )
     }
 }
 

macos/OpenBridge/Interface/Settings/General/GeneralSettingsView.swift

@@ -4,7 +4,9 @@ import SwiftUI
 
 struct GeneralSettingsView: View {
     @Environment(SettingsManager.self) private var settingsManager
-    private var languages = Bundle.main.localizations.filter { $0 != "Base" }
+    private var languages: [String] {
+        AppLanguageSelection.availableLocalizations(from: Bundle.main.localizations)
+    }
 
     @State private var cachedLaunchAtLogin: Bool = false
 
@@ -160,18 +162,26 @@ extension GeneralSettingsView {
             )
     }
 
-    @ViewBuilder
     private var languageSetting: some View {
-        @Bindable var settingsManager = settingsManager
-        Picker("Language", selection: $settingsManager.language) {
+        Picker("Language", selection: languageSelection) {
             ForEach(languages, id: \.self) { code in
-                Text(displayName(for: code)).tag(code)
+                Text(AppLanguageSelection.displayName(for: code)).tag(code)
             }
         }
     }
 
-    private func displayName(for code: String) -> String {
-        Locale.current.localizedString(forIdentifier: code) ?? code
+    private var languageSelection: Binding<String> {
+        Binding(
+            get: {
+                AppLanguageSelection.resolvedSelection(
+                    for: settingsManager.language,
+                    availableLocalizations: languages
+                )
+            },
+            set: { language in
+                settingsManager.language = language
+            }
+        )
     }
 }
 

macos/OpenBridgeUnitTests/Suites/AppLanguageSelectionTests.swift

@@ -0,0 +1,55 @@
+import Foundation
+@testable import OpenBridge
+import Testing
+
+struct AppLanguageSelectionTests {
+    @Test
+    func `available localizations remove base and preserve app option identifiers`() {
+        let localizations = AppLanguageSelection.availableLocalizations(from: ["Base", "en", "zh_Hans", "en"])
+
+        #expect(localizations == ["en", "zh-Hans"])
+    }
+
+    @Test
+    func `regional stored language resolves to supported picker option`() {
+        let available = ["en", "zh-Hans"]
+
+        #expect(
+            AppLanguageSelection.resolvedSelection(
+                for: "zh-Hans-CN",
+                availableLocalizations: available,
+                preferredLanguages: []
+            ) == "zh-Hans"
+        )
+        #expect(
+            AppLanguageSelection.resolvedSelection(
+                for: "en-US",
+                availableLocalizations: available,
+                preferredLanguages: []
+            ) == "en"
+        )
+    }
+
+    @Test
+    func `empty stored language resolves to preferred supported picker option`() {
+        let resolved = AppLanguageSelection.resolvedSelection(
+            for: "",
+            availableLocalizations: ["en", "zh-Hans"],
+            preferredLanguages: ["zh-Hans-CN"]
+        )
+
+        #expect(resolved == "zh-Hans")
+        #expect(!AppLanguageSelection.displayName(for: resolved, locale: Locale(identifier: "en_US_POSIX")).isEmpty)
+    }
+
+    @Test
+    func `unsupported stored language falls back to a visible supported option`() {
+        let resolved = AppLanguageSelection.resolvedSelection(
+            for: "es-MX",
+            availableLocalizations: ["en", "zh-Hans"],
+            preferredLanguages: []
+        )
+
+        #expect(resolved == "en")
+    }
+}