feat: iCloud settings sync and cold-start return redesign

- Add iCloud key-value settings sync (engine/language/polish/Flow prefs);
  API keys stay on-device. New "Sync settings via iCloud" toggle.
- Redesign cold-start handoff: bottom-bar left-to-right swipe guidance,
  auto-dismiss on app switch, tap-anywhere to close, retained return link.
- Harden keyboard->app handoff with host-disconnected hint.
- Include prior Unreleased ASR fixes (route-change crash, fallback warning,
  multi-utterance recognition, local ASR diagnostics).

Release 0.5.0 (build 18).

OSGKeyboardShared/Models/ProviderConfig.swift

@@ -78,6 +78,11 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
             guard !isApplyingConfiguration,
                   hasCompletedOnboarding != configuration.hasCompletedOnboarding else { return }
             configuration.hasCompletedOnboarding = hasCompletedOnboarding
+            // Mirror to the reboot-durable Keychain marker so a device restart
+            // can never resurrect the onboarding flow (or lose a replay reset).
+            let newValue = hasCompletedOnboarding
+            OSGLog.config.info("[onboarding] didSet → \(newValue, privacy: .public), mirroring to Keychain")
+            Keychain.setOnboardingCompleted(hasCompletedOnboarding)
             if hasCompletedOnboarding {
                 configuration.onboardingPage = 0
                 onboardingPage = 0
@@ -190,6 +195,19 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         }
     }
 
+    /// Diagnostic switch: disable to isolate whether the custom language model
+    /// is causing local SpeechAnalyzer to return empty results.
+    @Published public var localASRCustomLanguageModelEnabled: Bool {
+        didSet {
+            guard !isApplyingConfiguration,
+                  localASRCustomLanguageModelEnabled != configuration.localASRCustomLanguageModelEnabled else {
+                return
+            }
+            configuration.localASRCustomLanguageModelEnabled = localASRCustomLanguageModelEnabled
+            persistConfiguration()
+        }
+    }
+
     public var isConfigured: Bool {
         // Local engine uses on-device ASR + built-in DeepSeek polish and
         // does not need a user API key. Cloud needs base URL, key, and model.
@@ -221,6 +239,28 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         self.defaults = resolvedDefaults
         self.configuration = AppGroupConfiguration.load(fromAvailable: resolvedDefaults)
 
+        // Onboarding completion must survive a device reboot. App Group
+        // UserDefaults can transiently read empty right after boot, which would
+        // falsely re-show onboarding. Trust the durable Keychain marker when the
+        // App Group value looks unset, and backfill it once the App Group value
+        // is confirmed true (covers users onboarded before this safeguard).
+        let appGroupOnboarding = configuration.hasCompletedOnboarding
+        let keychainOnboarding = Keychain.hasCompletedOnboarding()
+        // Distinguish "key absent" (nil → plist not loaded / data-protection race)
+        // from "key present == false" (something actually wrote false).
+        let rawKeyPresent = resolvedDefaults.object(forKey: AppGroupConfiguration.Keys.hasCompletedOnboarding) != nil
+        OSGLog.config.info(
+            "[onboarding] init: appGroup=\(appGroupOnboarding, privacy: .public) (keyPresent=\(rawKeyPresent, privacy: .public)), keychain=\(keychainOnboarding, privacy: .public)"
+        )
+        if appGroupOnboarding {
+            Keychain.setOnboardingCompleted(true)
+        } else if keychainOnboarding {
+            configuration.hasCompletedOnboarding = true
+            OSGLog.config.info("[onboarding] init: App Group read false but Keychain true → restored to true")
+        }
+        let finalOnboarding = configuration.hasCompletedOnboarding
+        OSGLog.config.info("[onboarding] init: final=\(finalOnboarding, privacy: .public)")
+
         isApplyingConfiguration = true
         providerId = configuration.providerId
         baseURL = configuration.baseURL
@@ -239,6 +279,7 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         polishIntensity = configuration.polishIntensity
         flowSkipAppSwitch = configuration.flowSkipAppSwitch
         flowInactivityDuration = configuration.flowInactivityDuration
+        localASRCustomLanguageModelEnabled = configuration.localASRCustomLanguageModelEnabled
         isApplyingConfiguration = false
     }
 
@@ -255,6 +296,55 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         if postConfigChanged {
             AppGroupConfigDarwin.postConfigChanged()
         }
+        scheduleSettingsCloudPushIfEnabled()
+    }
+
+    /// Re-read App Group defaults after a cloud pull updates the cache.
+    public func reloadFromPersistedStorage() {
+        var fresh = AppGroupConfiguration.load(fromAvailable: defaults)
+        // Keep the reboot-durable onboarding marker authoritative across cloud
+        // pulls, matching the resilience applied at init.
+        let freshOnboarding = fresh.hasCompletedOnboarding
+        let keychainOnboarding = Keychain.hasCompletedOnboarding()
+        OSGLog.config.info(
+            "[onboarding] reload: appGroup=\(freshOnboarding, privacy: .public), keychain=\(keychainOnboarding, privacy: .public)"
+        )
+        if freshOnboarding {
+            Keychain.setOnboardingCompleted(true)
+        } else if keychainOnboarding {
+            fresh.hasCompletedOnboarding = true
+            OSGLog.config.info("[onboarding] reload: App Group read false but Keychain true → restored to true")
+        }
+        isApplyingConfiguration = true
+        configuration = fresh
+        providerId = fresh.providerId
+        baseURL = fresh.baseURL
+        model = fresh.model
+        modeId = fresh.modeId
+        localeId = fresh.localeId
+        engineMode = fresh.engineMode
+        hasCompletedOnboarding = fresh.hasCompletedOnboarding
+        onboardingPage = fresh.onboardingPage
+        hasAcknowledgedCloudSharing = fresh.hasAcknowledgedCloudSharing
+        uiLanguage = fresh.uiLanguage
+        translationTargetLocaleId = fresh.translationTargetLocaleId
+        handednessPreference = fresh.handednessPreference
+        cursorDragNavigationEnabled = fresh.cursorDragNavigationEnabled
+        polishIntensity = fresh.polishIntensity
+        flowSkipAppSwitch = fresh.flowSkipAppSwitch
+        flowInactivityDuration = fresh.flowInactivityDuration
+        localASRCustomLanguageModelEnabled = fresh.localASRCustomLanguageModelEnabled
+        isSyncingProviderAPIKey = true
+        apiKey = fresh.apiKey
+        isSyncingProviderAPIKey = false
+        isApplyingConfiguration = false
+    }
+
+    private func scheduleSettingsCloudPushIfEnabled() {
+        guard configuration.settingsICloudSyncEnabled else { return }
+        Task { @MainActor in
+            try? await SettingsCloudSync.shared.pushLocalIfEnabled()
+        }
     }
 
     public func apply(preset: LLMProvider) {
@@ -284,11 +374,13 @@ public final class ProviderConfig: ObservableObject, @unchecked Sendable {
         apiKey = ""
         model = preset.defaultModel
         handednessPreference = .left
+        localASRCustomLanguageModelEnabled = true
         hasAcknowledgedCloudSharing = false
         configuration.providerId = preset.id
         configuration.baseURL = preset.defaultBaseURL
         configuration.model = preset.defaultModel
         configuration.handednessPreference = .left
+        configuration.localASRCustomLanguageModelEnabled = true
         configuration.hasAcknowledgedCloudSharing = false
         isApplyingConfiguration = false
         persistConfiguration()