use utf-8 encoding for logging

[kristol07]

fix exception when logging because of encoding issue

[kristol07]

windows平台下会遇到logging的exception，需要设置utf-8 encoding。

[021gink]

下面的env文件读取也需要改一下utf-8 encoding：
def save_settings(self):
"""保存设置到.env文件"""
api_key = self.get_api_key()

    if not api_key:
        self.log_view.setPlainText("API Key不能为空")
        return
        
    try:
        # 读取现有.env内容
        env_lines = []
        if os.path.exists('.env'):
            with open('.env', 'r', encoding='utf-8') as f:
                env_lines = f.readlines()
        
        # 更新或添加SILICONFLOW_API_KEY
        found = False
        with open('.env', 'w', encoding='utf-8') as f:
            for line in env_lines:
                if line.startswith('SILICONFLOW_API_KEY='):
                    f.write(f'SILICONFLOW_API_KEY={api_key}\n')
                    found = True
                else:
                    f.write(line)
            if not found:
                f.write(f'\nSILICONFLOW_API_KEY={api_key}\n')
                
        self.log_view.setPlainText("设置保存成功")
        self.reload_env()  # 重新加载环境变量
    except Exception as e:
        self.log_view.setPlainText(f"保存失败：{str(e)}")
        
        同时启动函数改为python_path启动不会导致电脑python版本不一致引起的 Traceback (most recent call last): File "D:\Whisper-Input\main.py", line 8, in <module> from src.audio.recorder import AudioRecorder File "D:\Whisper-Input\src\audio\__init__.py", line 10, in <module> from .recorder import AudioRecorder File "D:\Whisper-Input\src\audio\recorder.py", line 2, in <module> import sounddevice as sd ModuleNotFoundError: No module named 'sounddevice'失败问题。
        
         import sys
         def start_main(self):
    """启动main.py"""
    if not self.check_env_file():
        return
        
    if not self.get_api_key():
        self.log_view.setPlainText("请先输入SILICONFLOW API Key")
        return
        
    if self.process is None:
        logger.info("启动主程序")
        # 使用sys.executable获取当前Python解释器的路径
        python_path = sys.executable
        self.process = subprocess.Popen([python_path, "main.py"])
        self.start_btn.setEnabled(False)
        self.stop_btn.setEnabled(True)
        
        # 初始化日志显示
        self.update_log_view()