feat(dictionary): add iCloud KVS sync, cloud ASR, and lexicon expansion

Mirror the personal dictionary through iCloud Key-Value Store with
deterministic merge rules, main-app-only sync UI, and App Group as the
keyboard runtime cache. Add cloud-engine ASR with dictionary bias and
expand the bundled custom language model lexicon.

OSGKeyboardShared/Services/LiveDictationController.swift

@@ -115,7 +115,7 @@ public final class LiveDictationController: ObservableObject {
     private var didInstallTap = false
 
     public init(asr: ASRService? = nil) {
-        self.asr = asr ?? ASRServiceFactory.make()
+        self.asr = asr ?? ASRServiceFactory.make(store: AppGroupStore())
     }
 
     /// Start dictation using a persisted settings locale id (`auto`, `zh-Hans`, …).