An install that predates the split holds canvases whose nodes carry the device
facts inline, with no `devices` key at all. Reading one already worked; nothing
pinned that the next save converts it in place rather than writing the old
shape back.
Covers the load-then-save round trip with every fact intact, the second save
not minting a duplicate row, furniture staying out of the conversion, and the
legacy bare-key canvas carried through `ensureSeed`.
ha-relevant: no
Pouzor
9db8b2a7a9