Authoring descriptors

Two paths, same output, a device package (§4):

1. By hand. Copy the package template, fill in the frontmatter and limits, write the operating procedure in DEVICE.md.
2. By interview. The agent asks the owner a short set of questions and writes the package: What is it and when should an agent pick it? Where does it sit? What is heavy, hot, sharp or fragile about it? How do you run it, step by step? What must be true before it runs? What values would you never set? What should always need a human? The first answer becomes description, the procedure becomes the DEVICE.md body, and the rest become notes, interlocks, limits and approval levels in descriptor.yaml. Existing SOPs and manual excerpts go under references/. The owner reviews the package before it is served.

Packages are versioned folders checked into the lab's repository. Changing a limit is a code review, not a runtime action.