feat: macOS architecture, cloud ASR/LLM providers, and 6-step iOS onboarding

- Add macOS menu-bar dictation app with local ASR models (SenseVoice/Qwen3),
  global Option hotkey, and bottom overlay
- Add cloud ASR/LLM providers (Anthropic, Volcengine, Bailian, and more) with
  provider logos, model listing, and connection checks
- Add shared 7-day usage stats UI (UsageStatsCluster / SevenDayUsageChart)
- Add iOS onboarding step 6 for polish LLM setup; hide custom-language-model
  diagnostic toggle behind DEBUG
- Unify iOS onboarding tagline with the macOS brand line ("开口即文字。")
- Rewrite README (Chinese-first, product-oriented) and refresh GitHub Pages

OSGKeyboardShared/Services/ICloudSync/SettingsCloudSync.swift

@@ -62,9 +62,10 @@ public final class SettingsCloudSync {
     public func enableSync() async throws {
         let store = makeStore()
         ICloudSyncPreferences.pushSettingsEnabled(true, kvs: kvs)
+        ICloudSyncPreferences.pushDictionaryEnabled(true, kvs: kvs)
         ICloudSyncPreferences.cacheToAppGroup(
             settingsEnabled: true,
-            dictionaryEnabled: store.personalDictionaryICloudSyncEnabled,
+            dictionaryEnabled: true,
             store: store
         )
 
@@ -93,7 +94,9 @@ public final class SettingsCloudSync {
     public func disableSync() {
         let store = makeStore()
         ICloudSyncPreferences.pushSettingsEnabled(false, kvs: kvs)
+        ICloudSyncPreferences.pushDictionaryEnabled(false, kvs: kvs)
         store.setSettingsICloudSyncEnabled(false)
+        store.setPersonalDictionaryICloudSyncEnabled(false)
     }
 
     public func pullAndMerge(store: AppGroupStore) async {