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/Services/PersonalDictionaryCloudSync/UbiquitousKeyValueStoreing.swift

@@ -8,6 +8,8 @@ import Foundation
 public protocol UbiquitousKeyValueStoreing: AnyObject {
     func data(forKey key: String) -> Data?
     func set(_ value: Data?, forKey key: String)
+    func object(forKey key: String) -> Any?
+    func set(_ value: Any?, forKey key: String)
     @discardableResult
     func synchronize() -> Bool
 }