feat(keyboard): improve typing, voice flow, and polish reliability

Reduce extension memory pressure and delivery races while adding richer candidates, tactile feedback, and safer two-level creative polishing.

OSGKeyboardHostSupport/Services/CloudASR/CloudASRConnectionCheck.swift

@@ -0,0 +1,22 @@
+// CloudASRConnectionCheck.swift
+// OSGKeyboard · Shared
+//
+// Settings "validate connection" probe shared by iOS and macOS.
+
+import Foundation
+#if canImport(OSGKeyboardShared)
+import OSGKeyboardShared
+#endif
+
+public enum CloudASRConnectionCheck {
+    /// Verifies the active cloud ASR client can connect + authenticate.
+    ///
+    /// Each backend decides how to probe (see `CloudASRTranscribing`):
+    /// HTTP/batch providers transcribe a short silence clip and treat an
+    /// empty transcript as success; Bailian / Volcengine / OpenAI Realtime
+    /// handshake (and auth) only — silence clips make streaming backends fail.
+    public static func validate(store: any ConfigurationStore) async throws {
+        let client = CloudASRClientFactory.make(store: store)
+        try await client.probeConnection()
+    }
+}