Working with a project sandbox

This is knowledge, not an action — there is nothing to run. Read it, then follow the conventions below for the rest of the session.

The sandbox rule

All software development work in this project happens inside its Docker sandbox container, never on the host. Concretely, on the host you must never:

• Install packages or toolchains (apt install, npm install -g, pip install, …)
• Run build tools, compilers, dev servers, or test suites directly
• Start services or daemons that bind host ports (except ones explicitly published in sandbox/docker-compose.yml)

The only host-side actions are: managing the sandbox container itself (sandbox/sandbox.sh ...), editing files in the project's own directory, and git operations on the project's own repo.