release-1.2.1

*Added DeepSeek model to adapt the reasoning process fix #64
*Added DeepSeek automatic hiding reasoning option
*Added advanced markdown syntax support fix #11, fix #27, fix #42
*Added multi-image function
*Added gpt-4.5-preview-2025-02-27, o3-mini-2025-01-31, o1
*Added gemini-2.0-flash-001, gemini-2.0-flash-lite-001, gemini-2.0-flash-exp, gemini-2.0-pro-exp-02-05
*Added claude-3-7-sonnet-20250219
*Fixed occasional flashback when stopping streaming output
*Fixed abnormal display of added pictures in chat page

*增加DeepSeek模型，适配推理过程 fix #64
*增加DeepSeek自动隐藏推理选项
*增加高级markdown语法支持 fix #11, fix #27, fix #42
*增加多图功能
*增加gpt-4.5-preview-2025-02-27、o3-mini-2025-01-31、o1
*增加gemini-2.0-flash-001、gemini-2.0-flash-lite-001、gemini-2.0-flash-exp、gemini-2.0-pro-exp-02-05
*增加claude-3-7-sonnet-20250219
*修复停止流式输出偶发闪退
*修复聊天页面添加图片图片异常显示