refactor(voice): isolate gemini live provider core

src/voice/commands.js

@@ -2,26 +2,17 @@ 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';
 
-/** Standalone provider selection; embedders may still supply their own adapter. */
-export function createVoiceCommands(options) {
-  if (options.createSession) return bindVoiceCommands(options);
-  const factories = {
-    openai: createRealtimeSession,
-    gemini: createGeminiSession,
-  };
-  const supportedProviders = supportedVoiceProviders(
-    options.supportedProviders,
-    factories,
-  );
-  return createProviderCommands(
-    { ...options, supportedProviders },
-    {
+/** Default composition; callers may supply another session adapter factory. */
+export function createVoiceCommands(options = {}) {
+  // Generic hosts retain the existing default; standalone opts in explicitly.
+  if (!options.createSession && options.supportedProviders !== undefined)
+    return createProviderCommands(options, {
       bind: bindVoiceCommands,
-      factories: Object.fromEntries(
-        supportedProviders.map((name) => [name, factories[name]]),
-      ),
-    },
-  );
+      factories: { openai: createRealtimeSession, gemini: createGeminiSession },
+    });
+  return bindVoiceCommands({
+    createSession: createRealtimeSession,
+    ...options,
+  });
 }