chore: align iOS 26 capability docs and UI localization

Keep repository messaging consistent with the implemented iOS 26 SpeechAnalyzer path, and remove mixed hardcoded copy by routing remaining UI/error text through localized string keys.

OSGKeyboard/Views/APISettingsCard.swift

@@ -24,7 +24,7 @@ struct APISettingsCard: View {
     var body: some View {
         VStack(spacing: 0) {
             field(
-                title: "Base URL · 接口地址",
+                title: NSLocalizedString("api.baseUrl", comment: ""),
                 placeholder: "https://api.openai.com/v1",
                 text: $config.baseURL,
                 autocap: false
@@ -33,7 +33,7 @@ struct APISettingsCard: View {
             keyField
             Divider().background(palette.divider)
             field(
-                title: "Model · 模型",
+                title: NSLocalizedString("api.model", comment: ""),
                 placeholder: "gpt-4o-mini",
                 text: $config.model,
                 autocap: false
@@ -41,7 +41,7 @@ struct APISettingsCard: View {
             if let url = LLMProvider.provider(id: config.providerId).apiKeyURL {
                 Divider().background(palette.divider)
                 // Use a Button + UIApplication.open instead of SwiftUI
-                // `Link`. SwiftUI `Link` has a hit-test bug on iOS 18 that
+                // `Link`. SwiftUI `Link` can have hit-test quirks on some
                 // makes its tappable area eat gestures from the adjacent
                 // TextField, which manifests as "typing jumps to a website".
                 Button {
@@ -86,7 +86,9 @@ struct APISettingsCard: View {
                         .foregroundStyle(palette.textSecondary)
                 }
                 .buttonStyle(.plain)
-                .accessibilityLabel(Text(showKey ? "隐藏密钥 · Hide key" : "显示密钥 · Show key"))
+                .accessibilityLabel(Text(showKey
+                    ? NSLocalizedString("api.key.hide", comment: "")
+                    : NSLocalizedString("api.key.show", comment: "")))
             }
             Group {
                 if showKey {
@@ -120,7 +122,7 @@ struct APISettingsCard: View {
                 .foregroundStyle(palette.textSecondary)
             // `.asciiCapable` is the *minimum* contract for these fields:
             // API keys, base URLs, and model names are all ASCII by spec,
-            // and SwiftUI's `.URL` keyboard on iOS 18 still occasionally
+            // and SwiftUI's `.URL` keyboard can still occasionally
             // hands control to the system keyboard which then auto-suggests
             // Chinese / emoji completions that corrupt the value. Forcing
             // `.asciiCapable` keeps the system out of the way.
@@ -132,7 +134,7 @@ struct APISettingsCard: View {
                 .foregroundStyle(palette.textPrimary)
                 .submitLabel(.done)
                 .onSubmit { /* no-op: prevent the keyboard from "submitting"
-                              and dismissing the sheet on iOS 18 */ }
+                              and dismissing the sheet unexpectedly */ }
         }
         .padding(.horizontal, Spacing.md)
         .padding(.vertical, Spacing.sm)

OSGKeyboard/Views/EnginePickerSection.swift

@@ -33,15 +33,15 @@ struct EnginePickerSection: View {
                 engineOptionRow(
                     id: "local",
                     icon: "iphone.badge.checkmark",
-                    title: "本地识别 · On-device",
+                    title: NSLocalizedString("settings.engine.local.title", comment: ""),
                     subtitle: localSubtitle
                 )
                 Divider().background(palette.divider)
                 engineOptionRow(
                     id: "cloud",
                     icon: "wand.and.stars",
-                    title: "云端润色 · Cloud polish",
-                    subtitle: "ASR 转录 + LLM 润色,需要 API Key\nASR + LLM polish, API key required"
+                    title: NSLocalizedString("settings.engine.cloud.title", comment: ""),
+                    subtitle: NSLocalizedString("settings.engine.cloud.subtitle", comment: "")
                 )
             }
             .background(palette.surface, in: RoundedRectangle(cornerRadius: Radius.large, style: .continuous))
@@ -55,7 +55,7 @@ struct EnginePickerSection: View {
     private var localSubtitle: String {
         // iOS 26's `SpeechAnalyzer` is always fully on-device, so the
         // local engine's only contract is "no network, no LLM".
-        "SpeechAnalyzer · 始终端侧,无需联网\nAlways on-device, no network"
+        NSLocalizedString("settings.engine.local.ios26", comment: "")
     }
 
     private func engineOptionRow(id: String, icon: String, title: String, subtitle: String) -> some View {

OSGKeyboard/Views/HomeView.swift

@@ -45,7 +45,7 @@ struct HomeView: View {
                 Circle()
                     .fill(config.isConfigured ? palette.success : palette.warning)
                     .frame(width: 8, height: 8)
-                Text(config.isConfigured ? "就绪 · Ready" : "未完成配置 · Setup incomplete")
+                Text(config.isConfigured ? "home.status.ready" : "home.status.setupIncomplete")
                     .font(TypeStyle.caption)
                     .foregroundStyle(palette.textSecondary)
             }

OSGKeyboard/Views/KeyboardPreviewSheet.swift

@@ -4,14 +4,15 @@
 // In-app preview of the keyboard extension. Renders a stand-in
 // `KeyboardPreviewStub` so the user can see what the real extension
 // looks like, AND drives a *real* `PreviewASRController` so tapping
-// the disc actually records from the mic, runs SFSpeechRecognizer,
+// the disc actually records from the mic and runs the shared ASR
+// service (`SpeechAnalyzer` on iOS 26+),
 // and lands recognized text in the top textbox. Without the real ASR
 // the preview was a static mock — "the text never appears" was a
 // fair review note.
 //
 // Lifecycle (local engine = "transcribe" only, no LLM):
 //   tap → start ASR (idempotent re-entry guard)
-//        → SFSpeechRecognizer emits .partial / .final
+//        → ASR emits .partial / .final
 //        → currentPartial updates the transcript line in real time
 //   tap → stop ASR
 //        → lastFinal event lands

OSGKeyboard/Views/OnboardingView.swift

@@ -9,7 +9,8 @@
 //
 // We deliberately do NOT use `TabView` with `.page` style for the
 // pager. That style wraps the content in a `UIPageViewController`,
-// and `UIPageViewController` has a long-standing iOS 18 bug where
+// and `UIPageViewController` has a long-standing behavior on some iOS
+// versions where
 // the keyboard-showing layout reflow on a `TextField` focus is
 // misread as a horizontal swipe — the page jumps back to step 1
 // the moment the user starts typing. Replacing the TabView with a
@@ -136,10 +137,6 @@ private struct WelcomePage: View {
                     .font(TypeStyle.body)
                     .foregroundStyle(palette.textSecondary)
                     .multilineTextAlignment(.center)
-                Text("onboarding.welcome.subtitle")
-                    .font(TypeStyle.footnote)
-                    .foregroundStyle(palette.textTertiary)
-                    .multilineTextAlignment(.center)
             }
             .padding(.horizontal, Spacing.xl)
             PrivacyFootnote()
@@ -210,15 +207,12 @@ private struct EnableKeyboardPage: View {
                 Text("onboarding.enable.title")
                     .font(TypeStyle.title2)
                     .foregroundStyle(palette.textPrimary)
-                Text("onboarding.enable.title")
-                    .font(TypeStyle.body)
-                    .foregroundStyle(palette.textTertiary)
             }
             VStack(alignment: .leading, spacing: Spacing.sm) {
-                step(num: 1, text: "设置 → 通用 → 键盘 → 键盘")
-                step(num: 2, text: "点击「添加新键盘…」并选择 OSGKeyboard")
-                step(num: 3, text: "点击 OSGKeyboard 并启用「允许完全访问」")
-                step(num: 4, text: "Allow Full Access is required for microphone + LLM calls · 允许完全访问是麦克风和网络调用的前提")
+                step(num: 1, text: NSLocalizedString("onboarding.enable.step1", comment: ""))
+                step(num: 2, text: NSLocalizedString("onboarding.enable.step2", comment: ""))
+                step(num: 3, text: NSLocalizedString("onboarding.enable.step3", comment: ""))
+                step(num: 4, text: NSLocalizedString("onboarding.enable.step4", comment: ""))
             }
             .cardSurface()
             .padding(.horizontal, Spacing.md)
@@ -228,7 +222,7 @@ private struct EnableKeyboardPage: View {
                     UIApplication.shared.open(url)
                 }
             } label: {
-                Label("打开 iOS 设置 · Open Settings", systemImage: "arrow.up.right.square")
+                Label(LocalizedStringKey("onboarding.enable.openSettings"), systemImage: "arrow.up.right.square")
                     .primaryButton()
             }
             .padding(.horizontal, Spacing.md)

OSGKeyboard/Views/PreviewASRController.swift

@@ -133,7 +133,10 @@ final class PreviewASRController: ObservableObject {
                 try session.setActive(true, options: .notifyOthersOnDeactivation)
                 didConfigureAudioSession = true
             } catch {
-                phase = .error("Audio session 错误 · Audio session error: \(error.localizedDescription)")
+                phase = .error(String.localizedStringWithFormat(
+                    NSLocalizedString("preview.error.audioSession", comment: ""),
+                    error.localizedDescription
+                ))
                 return
             }
         }
@@ -219,7 +222,11 @@ final class PreviewASRController: ObservableObject {
         // state from a previous foreground/background transition.
         guard hwFormat.sampleRate > 0, hwFormat.channelCount > 0 else {
             phase = .error(
-                "麦克风不可用 · Microphone unavailable (hw format \(hwFormat.sampleRate) Hz / \(hwFormat.channelCount) ch)"
+                String.localizedStringWithFormat(
+                    NSLocalizedString("preview.error.micUnavailable", comment: ""),
+                    hwFormat.sampleRate,
+                    Int(hwFormat.channelCount)
+                )
             )
             return
         }
@@ -231,11 +238,11 @@ final class PreviewASRController: ObservableObject {
             channels: 1,
             interleaved: false
         ) else {
-            phase = .error("无法创建 16 kHz 音频格式")
+            phase = .error(NSLocalizedString("preview.error.formatCreate", comment: ""))
             return
         }
         guard let converter = AVAudioConverter(from: hwFormat, to: targetFormat) else {
-            phase = .error("无法创建音频转换器")
+            phase = .error(NSLocalizedString("preview.error.converterCreate", comment: ""))
             return
         }
 
@@ -280,7 +287,10 @@ final class PreviewASRController: ObservableObject {
         do {
             try audioEngine.start()
         } catch {
-            phase = .error("无法启动音频引擎 · Engine start failed: \(error.localizedDescription)")
+            phase = .error(String.localizedStringWithFormat(
+                NSLocalizedString("preview.error.engineStart", comment: ""),
+                error.localizedDescription
+            ))
             return
         }
 

OSGKeyboard/Views/SettingsView.swift

@@ -83,7 +83,7 @@ struct SettingsView: View {
 
     private var apiSection: some View {
         VStack(alignment: .leading, spacing: Spacing.xs) {
-            sectionHeader("API · 接口", subtitle: nil)
+            sectionHeader("settings.api.title", subtitle: nil)
             APISettingsCard(config: config)
         }
     }
@@ -91,12 +91,15 @@ struct SettingsView: View {
     // MARK: - Language (ASR + mode)
 
     private var languageSection: some View {
-        VStack(alignment: .leading, spacing: Spacing.xs) {
-            sectionHeader("Language · 语言", subtitle: "选择识别语言\(config.engineMode == "cloud" ? "和文字处理模式" : "")。Recognition language\(config.engineMode == "cloud" ? " and text processing mode" : "").")
+        let subtitleKey: LocalizedStringKey = config.engineMode == "cloud"
+            ? "settings.language.subtitle.cloud"
+            : "settings.language.subtitle.local"
+        return VStack(alignment: .leading, spacing: Spacing.xs) {
+            sectionHeader("settings.language.title", subtitle: subtitleKey)
             VStack(spacing: 0) {
                 if config.engineMode == "cloud" {
                     PickerRow(
-                        title: "Mode · 模式",
+                        title: NSLocalizedString("settings.mode.title", comment: ""),
                         options: modeOptions,
                         selection: Binding(
                             get: { config.modeId },
@@ -121,7 +124,8 @@ struct SettingsView: View {
                     .stroke(palette.divider, lineWidth: 0.5)
             )
 
-            // Legend — only relevant for SFSpeechRecognizer path (iOS 18–25)
+            // Legacy legend block: kept for UI compatibility, but with
+            // iOS 26 as minimum target this branch never executes.
             if #unavailable(iOS 26) {
                 HStack(spacing: Spacing.xs) {
                     Image(systemName: "iphone")
@@ -146,8 +150,7 @@ struct SettingsView: View {
     /// ASR engine row. With iOS 26 as the deployment target, the
     /// only ASR backend is `SpeechAnalyzer` and it is always fully
     /// on-device — so this row is now a static badge rather than a
-    /// toggle. The previous `requiresOnDevice` toggle (iOS 18–25
-    /// `SFSpeechRecognizer` cloud-fallback control) is gone.
+    /// toggle. The old cloud-fallback toggle is gone.
     private var asrEngineRow: some View {
         HStack(spacing: Spacing.sm) {
             Text("settings.engineRow.title")
@@ -170,7 +173,7 @@ struct SettingsView: View {
         .padding(.vertical, Spacing.sm)
     }
 
-    /// Falls back to a static list while SFSpeechRecognizer locales are loading.
+    /// Falls back to a static list while dynamic locales are loading.
     private var effectiveLocales: [(id: String, label: String, onDevice: Bool)] {
         dynamicLocales.isEmpty ? staticLocales : dynamicLocales
     }
@@ -197,15 +200,15 @@ struct SettingsView: View {
     // MARK: - Dynamic locale loading
 
     private func loadDynamicLocales() async {
-        // Run everything in a background task: SFSpeechRecognizer.supportedLocales()
+        // Run everything in a background task: `SFSpeechRecognizer.supportedLocales()`
         // can return 100+ locales, and we probe supportsOnDeviceRecognition for each.
-        // Creating SFSpeechRecognizer instances in a @Sendable closure is safe —
-        // the existing ASRService.swift does the same thing inside AsyncStream { }.
+        // Creating `SFSpeechRecognizer` instances in a @Sendable closure is
+        // safe here; we only read locale metadata (no transcription session).
         let entries: [(id: String, label: String, onDevice: Bool)] = await Task.detached(
             priority: .userInitiated
         ) {
             var result: [(id: String, label: String, onDevice: Bool)] = []
-            result.append(("auto", "Auto · 跟随系统", false))
+            result.append(("auto", NSLocalizedString("locale.auto", comment: ""), false))
 
             let currentLocale = Locale.current  // snapshot on background thread is fine
             for locale in SFSpeechRecognizer.supportedLocales()
@@ -228,7 +231,7 @@ struct SettingsView: View {
     private var promptSection: some View {
         VStack(alignment: .leading, spacing: Spacing.xs) {
             HStack {
-                sectionHeader("System Prompt · 系统提示", subtitle: nil)
+                sectionHeader("settings.systemPrompt.title", subtitle: nil)
                 Spacer()
                 Button("common.reset") { config.systemPrompt = config.defaultSystemPrompt }
                     .font(TypeStyle.caption2)

OSGKeyboard/en.lproj/Localizable.strings

@@ -111,6 +111,11 @@
 "preview.openSettingsA11y" = "Open OSGKeyboard settings";
 "preview.modeChip.cycle" = "Cycle input mode";
 "preview.localeChip.cycle" = "Cycle recognition language";
+"preview.error.audioSession" = "Audio session error: %@";
+"preview.error.micUnavailable" = "Microphone unavailable (hw format %.0f Hz / %d ch)";
+"preview.error.formatCreate" = "Failed to create 16 kHz audio format.";
+"preview.error.converterCreate" = "Failed to create audio converter.";
+"preview.error.engineStart" = "Engine start failed: %@";
 
 /* Keyboard (ext) */
 "keyboard.placeholder.idle" = "Hold to talk";

OSGKeyboard/zh-Hans.lproj/Localizable.strings

@@ -111,6 +111,11 @@
 "preview.openSettingsA11y" = "打开 OSGKeyboard 设置";
 "preview.modeChip.cycle" = "切换输入模式";
 "preview.localeChip.cycle" = "切换识别语言";
+"preview.error.audioSession" = "音频会话错误: %@";
+"preview.error.micUnavailable" = "麦克风不可用 (硬件格式 %.0f Hz / %d 声道)";
+"preview.error.formatCreate" = "无法创建 16 kHz 音频格式。";
+"preview.error.converterCreate" = "无法创建音频转换器。";
+"preview.error.engineStart" = "无法启动音频引擎: %@";
 
 /* Keyboard (ext) */
 "keyboard.placeholder.idle" = "按住说话";