apparently I need to do this myself

Dockerfile

@@ -52,19 +52,19 @@ RUN mkdir -p /var/run/sshd && \
 # Custom sshd_config for non-root usage
 # StrictModes no: Required for non-root / random UID environments
 # PidFile: Point to /tmp for guaranteed write access
-RUN echo "Port 2222
-PermitRootLogin no
-PasswordAuthentication no
-PubkeyAuthentication yes
-StrictModes no
-PidFile /tmp/sshd.pid
-HostKey /data/ssh/ssh_host_rsa_key
-HostKey /data/ssh/ssh_host_ecdsa_key
-HostKey /data/ssh/ssh_host_ed25519_key
-AuthorizedKeysFile .ssh/authorized_keys
-ChallengeResponseAuthentication no
-UsePAM yes
-Subsystem sftp /usr/lib/openssh/sftp-server" > /etc/ssh/sshd_config
+RUN echo "Port 2222 \
+  PermitRootLogin no \
+  PasswordAuthentication no \
+  PubkeyAuthentication yes \
+  StrictModes no \
+  PidFile /tmp/sshd.pid \
+  HostKey /data/ssh/ssh_host_rsa_key \
+  HostKey /data/ssh/ssh_host_ecdsa_key \
+  HostKey /data/ssh/ssh_host_ed25519_key \
+  AuthorizedKeysFile .ssh/authorized_keys \
+  ChallengeResponseAuthentication no \
+  UsePAM yes \
+  Subsystem sftp /usr/lib/openssh/sftp-server" > /etc/ssh/sshd_config
 
 # Create a user 'claw' (UID 1000) with sudo access
 RUN useradd -m -s /bin/bash -u 1000 claw && \