311 - Self learning harnesses are here

Claude Code and Codex have been the mainstay. OpenCode and Pi showed what open-source harnesses could be. But two new entries just moved the goalposts: DeepSeek's Cordis kernel treats everything — even the agent loop itself — as a hot-swappable plugin, and Prime Agent runs the whole harness inside a live REPL where sub-agents are just function calls. Self-learning harnesses are here, and they're open source.