An approved inventory row is what canvas nodes and rack mounts point at,
under `ON DELETE SET NULL`. Both collapse paths kept the first approved
row of a duplicate group and deleted the rest, so a group holding two of
them lost one device's links silently — and grouping by shared address
rather than by the exact `ip` string made that group easy to form: an
approved `10.0.0.1` beside an approved `10.0.0.1, 10.0.0.2` is one.
`_collapse_targets` now picks the merge target and the rows that may go.
With one approved row nothing changes. With two, every approved row
stands and only the pending ones collapse: a background scan is not the
place to decide which canvas-linked device loses its links, and the pair
stays visible in the inventory for the user to resolve.
ha-relevant: yes
Pouzor
e1e7b5089b