Durable design briefs and exploration→plan docs for agent-driven work, mirroring
the ~/upsun/dephekt/agent-planning docs system (mkdocs + Material). One markdown
file per topic ("slug") under docs/briefs/; Mermaid diagrams render inline.
python3 -m venv .venv && . .venv/bin/activate
pip install -r requirements.txt
mkdocs serve # http://127.0.0.1:8000
mkdocs build # static site → site/docs/briefs/grow-control-system.md— MQTT/multi-site grow control architecture.