feat: generate key pair using ssh2 for right public key format

quests/Dockerfile

@@ -26,7 +26,7 @@ ENV USERNAME=commander
 
 RUN adduser --disabled-password --gecos '' --shell /bin/zsh ${USERNAME}
 COPY ./quests/sshd_config /etc/ssh/sshd_config
-COPY ./ssh_pubkey /home/${USERNAME}/.ssh/authorized_keys
+COPY ./config/ssh_key.pub /home/${USERNAME}/.ssh/authorized_keys
 RUN chmod 600 /home/${USERNAME}/.ssh/authorized_keys \
   && chmod 700 /home/${USERNAME}/.ssh \
   && chown -R ${USERNAME}:${USERNAME} /home/${USERNAME}/.ssh