[FEATURE] Add a --append-system-prompt-file <path> argument

I'm currently using:

claude --append-system-prompt "$(cat ROLE.md)" --permission-mode acceptEdits "Read the @SPEC.md file and start implementing the solution"

My role file is typically 30 to 200 lines of content.

The above command works but is not ideal. This is a feature request.

By adding a --append-system-prompt-file <path> argument, the command would become:

claude --append-system-prompt-file ROLE.md --permission-mode acceptEdits "Read the @SPEC.md file and start implementing the solution"