feat(v2): complete v2 reimplementation

tests/ssh-fixture/Dockerfile

@@ -0,0 +1,18 @@
+FROM debian:12-slim
+
+RUN apt-get update \
+    && DEBIAN_FRONTEND=noninteractive apt-get install --no-install-recommends -y openssh-server \
+    && rm -rf /var/lib/apt/lists/* \
+    && (getent group backup >/dev/null || groupadd --system backup) \
+    && (id backup >/dev/null 2>&1 || useradd --system --gid backup --home-dir /home/backup --shell /usr/sbin/nologin backup) \
+    && install -d -o root -g root -m 0755 /home/backup \
+    && install -d -o backup -g backup -m 0700 /home/backup/.ssh \
+    && install -d -o backup -g backup -m 0755 /home/backup/data \
+    && install -d -o root -g root -m 0755 /run/sshd
+
+COPY sshd_config /etc/ssh/sshd_config
+COPY entrypoint.sh /usr/local/bin/fixture-sshd
+RUN chmod 0755 /usr/local/bin/fixture-sshd
+
+EXPOSE 2222
+CMD ["/usr/local/bin/fixture-sshd"]