Gemini 3 Pro Preview Support

Minor Changes

• #1427 122c23a Thanks @Crunchyman-ralph! - Added Gemini 3 pro preview to supported Taskmaster AI providers
  • Added to Google providers
  • Added to Gemini CLI providers
    • Attention: Gemini 3 Pro is available for:
      • Google AI Ultra Subscribers
      • Users who have access via a paid Gemini API key
        • If you want to use the gemini api key, make sure you have this defined in your .env or mcp.json env variables: GEMINI_API_KEY=xxxx