feat(voice): harden Gemini Live provider integration

src/voice/commands.js

@@ -1,10 +1,27 @@
 import { createVoiceCommands as bindVoiceCommands } from './sessionCommands.js';
 import { createRealtimeSession } from './realtimeSession.js';
+import { createGeminiSession } from './geminiSession.js';
+import { createProviderCommands } from './providerCommands.js';
+import { supportedVoiceProviders } from './providerCapabilities.js';
 
-/** Default composition; callers may supply another session adapter factory. */
+/** Standalone provider selection; embedders may still supply their own adapter. */
 export function createVoiceCommands(options) {
-  return bindVoiceCommands({
-    createSession: createRealtimeSession,
-    ...options,
-  });
+  if (options.createSession) return bindVoiceCommands(options);
+  const factories = {
+    openai: createRealtimeSession,
+    gemini: createGeminiSession,
+  };
+  const supportedProviders = supportedVoiceProviders(
+    options.supportedProviders,
+    factories,
+  );
+  return createProviderCommands(
+    { ...options, supportedProviders },
+    {
+      bind: bindVoiceCommands,
+      factories: Object.fromEntries(
+        supportedProviders.map((name) => [name, factories[name]]),
+      ),
+    },
+  );
 }