New App Shelf

What else should run itself — for THIS shop, off THIS shop's files.

The screen behind the + on the rail ships twelve hardcoded tiles whose notes are numbers about an imagined business. This answers the same shape for a real one, and answers personalised: false with NO rows whenever it cannot — which is every one of:

• the tree could not be read (census.blind): the one failure this product has already paid for once, and never a shelf;
• the tree holds no number worth a tile;
• this deployment has no Pi harness;
• the turn has not finished inside wait, or came back unusable;
• every row it wrote quoted a number this shop's files do not carry.

A caller that wants to poll rather than hold the connection passes wait=0: the run is accepted and the answer says building. refresh=1 ignores a stored shelf and writes a new one for the same facts.