feat: update Dockerfile to use fixed user and enhance directory ownership; add push command to docker.py for DockerHub integration

docker/python-dev/Dockerfile

@@ -1,17 +1,16 @@
 FROM python:3.13
 
-ARG USERNAME=dev
 ARG UID=1000
 ARG GID=1000
 
 # Create user with sudo support
-RUN groupadd --gid $GID $USERNAME \
-    && useradd --uid $UID --gid $GID -m $USERNAME \
+RUN groupadd --gid $GID dev \
+    && useradd --uid $UID --gid $GID -m dev \
     && apt-get update \
     && apt-get install -y sudo curl gnupg \
-    && echo "$USERNAME ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/$USERNAME \
-    && chmod 0440 /etc/sudoers.d/$USERNAME \
-    && usermod -a -G dialout $USERNAME
+    && echo "dev ALL=(ALL) NOPASSWD:ALL" > /etc/sudoers.d/dev \
+    && chmod 0440 /etc/sudoers.d/dev \
+    && usermod -a -G dialout dev
 
 # Install system packages
 RUN apt-get install -y \
@@ -61,26 +60,32 @@ ENV LANG=en_US.UTF-8
 ENV LC_ALL=en_US.UTF-8
 
 # Create user directories with proper ownership
-RUN mkdir -p /home/${USERNAME}/.vscode-server/extensions \
-    && mkdir -p /home/${USERNAME}/.local/bin \
-    && mkdir -p /home/${USERNAME}/.claude \
+RUN mkdir -p /home/dev/.vscode-server/extensions \
+    && mkdir -p /home/dev/.local/bin \
+    && mkdir -p /home/dev/.claude \
     && mkdir -p /workspace \
     && mkdir -p /workspace/.venv \
-    && chown -R ${USERNAME}:${USERNAME} /home/${USERNAME}/.vscode-server \
-    && chown -R ${USERNAME}:${USERNAME} /home/${USERNAME}/.local \
-    && chown -R ${USERNAME}:${USERNAME} /home/${USERNAME}/.claude \
-    && chown -R ${USERNAME}:${USERNAME} /workspace
+    && chown -R dev:dev /home/dev/.vscode-server \
+    && chown -R dev:dev /home/dev/.local \
+    && chown -R dev:dev /home/dev/.claude \
+    && chown -R dev:dev /workspace
 
 VOLUME /workspace/.venv
 
-
-
 # Switch to non-root user (only once, for the rest of the build)
-USER ${USERNAME}
-WORKDIR /home/${USERNAME}
+USER dev
+
+# create ssh keys
+RUN ssh-keygen -q -t ed25519 -N "" -f /home/dev/.ssh/id_ed25519 && \
+    printf "Host *\n  StrictHostKeyChecking accept-new\n" > /home/dev/.ssh/config && \
+    chmod 0700 /home/dev/.ssh && \
+    chmod 0600 /home/dev/.ssh/id_ed25519 /home/dev/.ssh/config && \
+    chmod 0644 /home/dev/.ssh/id_ed25519.pub
+
+WORKDIR /home/dev
 
 # Add local bin to PATH
-ENV PATH="/home/${USERNAME}/.local/bin:${PATH}"
+ENV PATH="/home/dev/.local/bin:${PATH}"
 
 # Install uv
 RUN curl -LsSf https://astral.sh/uv/install.sh | sh
@@ -96,9 +101,9 @@ RUN curl -fsSL https://gh.io/copilot-install | bash
 RUN curl -fsSL https://claude.ai/install.sh | bash
 
 # User config (most frequently changed)
-COPY --chown=${USERNAME}:${USERNAME} CLAUDE.md /home/${USERNAME}/.claude/CLAUDE.md
-COPY --chown=${USERNAME}:${USERNAME} aliases.sh /home/${USERNAME}/.aliases.sh
-COPY --chown=${USERNAME}:${USERNAME} bash_helpers.sh /home/${USERNAME}/.bash_helpers.sh
+COPY --chown=dev:dev CLAUDE.md /home/dev/.claude/CLAUDE.md
+COPY --chown=dev:dev aliases.sh /home/dev/.aliases.sh
+COPY --chown=dev:dev bash_helpers.sh /home/dev/.bash_helpers.sh
 
 # Customize bash prompt
 RUN echo 'export PS1="${PROJECT_NAME:+\[\e[35m\][$PROJECT_NAME]\[\e[m\] }🐍 \[\e[33m\]\W\[\e[m\] \[\033[1;36m\]# \[\033[0m\]"' >> ~/.bashrc \