feat: add tool-images directory with Dockerfiles for all base tool types

- Create tool-images/ directory with organized Dockerfile templates
- Add base.dockerfile with common dev tools (git, nvim, ranger, tmux, node)
- Add code-server.dockerfile with VS Code in browser
- Add jupyter.dockerfile with Jupyter Lab
- Add opencode.dockerfile with OpenCode agent
- Add pi-agent.dockerfile with Pi Coding Agent (pi.dev)
- All images include: git, neovim, ranger, tmux, htop, tree, jq, Node.js 20
- Add README with usage instructions

tool-images/jupyter.dockerfile

@@ -0,0 +1,23 @@
+# Jupyter Notebook/Lab
+FROM jupyter/scipy-notebook:latest
+
+USER root
+
+# Install additional tools
+RUN apt-get update && apt-get install -y \
+    git \
+    neovim \
+    ranger \
+    tmux \
+    htop \
+    tree \
+    jq \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set up git
+RUN git config --global init.defaultBranch main
+
+# Switch back to jovyan user (default for scipy-notebook)
+USER ${NB_UID}
+
+EXPOSE 8888