Set secret values on one owned node for a scope (names come back)

S2: key → value, the values in this body and nowhere else (rule 1).

hide_input_in_errors keeps a value out of any rendered ValidationError, and every check below raises a sentence that names no key and no value: a value pasted into the key field must not come back in a 422 either. The 422 envelope drops input (app.py) but keeps loc, which is why values is typed Any and checked here: a typed dict would put the failing key into the location.

Which keys one scope holds, by name, and whether the node was reachable.

There is no value field and there is nowhere to put one: the daemon cannot return a value, and this cloud must not invent what it does not hold. The absence is the contract.