Add SuperClaude installation for user

- Install pipx in Dockerfile for Python package management
- Add SuperClaude installation in entrypoint.sh for each user
- SuperClaude runs with user permissions for better security

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

entrypoint.sh

@@ -55,6 +55,9 @@ set -e
 # clean chromium config for fresh start
 su - $XWINDOW_USER -c "rm -rf ~/.config/chromium/"   
 
+# install super-claude
+su - $XWINDOW_USER -c "pipx install SuperClaude && pipx upgrade SuperClaude && SuperClaude install"
+
 # start code-server in background
 su - $XWINDOW_USER -c "code-server --bind-addr 0.0.0.0:30145 --auth password /mnt" &