feat: Add character names to scenarios and UI

Introduces `characterName` to the `Scenario` type, enabling AI personas to be explicitly named. This change also updates the `ScenarioCard` component to display the character name and adds foundational support for potential future scenario deletion functionality. The README has been updated with a new AI Studio link.

components/VoiceSession/VoiceControls.tsx

@@ -0,0 +1,34 @@
+
+import React from 'react';
+import { Mic, MicOff, MessageSquare } from 'lucide-react';
+
+interface VoiceControlsProps {
+  isMuted: boolean;
+  onToggleMute: () => void;
+  showTranscript: boolean;
+  onToggleTranscript: () => void;
+}
+
+const VoiceControls: React.FC<VoiceControlsProps> = ({ 
+  isMuted, 
+  onToggleMute, 
+  showTranscript, 
+  onToggleTranscript 
+}) => (
+  <div className="p-8 flex justify-center gap-6 relative z-10 bg-black/20 backdrop-blur-md">
+    <button 
+      onClick={onToggleMute}
+      className={`p-5 rounded-full transition-all ${isMuted ? 'bg-rose-600 text-white' : 'bg-white/10 text-white hover:bg-white/20'}`}
+    >
+      {isMuted ? <MicOff size={24} /> : <Mic size={24} />}
+    </button>
+    <button 
+      onClick={onToggleTranscript}
+      className={`p-5 rounded-full transition-all ${showTranscript ? 'bg-teal-600 text-white' : 'bg-white/10 text-white hover:bg-white/20'}`}
+    >
+      <MessageSquare size={24} />
+    </button>
+  </div>
+);
+
+export default React.memo(VoiceControls);