Two sets of help
I had two places where my system explained itself. The Control Plane has a question-mark button on every screen with a description of that screen. And the family portal, a small site on the NAS that my family and I read when something in the house or the network needs explaining, has 83 pages in Dutch and English: the cameras, the backups, how the NAS is wired. The portal pages were 166 files in a folder outside the vault, in a block markup of their own (a ::table here, a ::note there).
Two sources meant two places to edit, and one of them was invisible to everything the vault does: search, links, properties, history.
One kind of document
Help became a note type. A screen description is a note with kind: screen-help, saved in a folder named after the screen, with its images and PDFs beside it. A portal page is a note with share: family-portal, in the area it belongs to: the house pages with the house, the travel pages with travel.
The portal still needs its own files, so a script exports every note flagged family-portal back to the portal's folder. It removes the properties the vault added and writes what the portal always had. The check compares the result with a backup of the original files, and zero differ. The nightly export reports how many files it wrote. A non-zero number would mean someone edited a note and the portal had not caught up. Today it wrote none of the 166.
The part that went wrong
The screen-help notes and the portal pages ended up in the same folder for the system area. The Screens tab listed everything in that folder as a screen: 250 screens where there were 202, because 48 of them were portal pages. The Screens tab now lists a note only if its kind is screen help. A folder says where a note is saved, and the kind says what it is.