- Edit tool now respects defaultFileEncoding for new files
- Edit tool preserves BOM character for existing files without re-adding
- AcpFileSystemService detects BOM through ACP client with fallback
- Use line: null, limit: 1 for efficient BOM detection
- Add unit tests for AcpFileSystemService.detectFileBOM
- Add unit tests for EditTool BOM handling
Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>