pub fn main() -> Result<(), String>Expand description
Entry point for the nichlink binary: dispatch this process’s own argv.
nichlink 二进制的入口：分发本进程自己的 argv。
Reads the real process arguments, writes the command’s report to stdout, and
returns a failure as Err so the binary decides the exit code.
读取真实进程参数，把命令报告写到 stdout，失败以 Err 返回，由二进制决定退出码。