fix: listening mode top text

[destucr]

🎯 Summary

This pull request introduces a minor UI improvement to the OrbLiveListenView in the Live Listen feature. When the app is actively listening, users now see a helpful prompt instructing them how to stop the session.

✨ Features/Changes

• Added user guidance text during active listening sessions
• Enhanced UX by displaying "Hold sphere to stop session" instruction
• Improved visual feedback for the Live Listen feature

📁 Files Changed

• Tiny/Features/LiveListen/Views/OrbLiveListenView.swift - Added VStack with subheadline text to display session stop instructions

🔧 Usage Examples (if applicable)

// When listening state is active, users will see:
VStack {
    // Existing listening UI components
    Text("Hold sphere to stop session")
        .font(.subheadline)
        .foregroundColor(.secondary)
}

🔗 Related Issues

Closes #