Monero's get_info returns target_height == 0 when the node is FULLY
SYNCED — the field is the height being caught up to, not the chain tip.
The '??' fallback left 0 in place, so every healthy node rendered
"Syncing — 0.00%, 0 blocks behind" forever. Treat 0/absent as
target = own height, the same sentinel electrs_status.rs branches on.
ssmithx
10b11d29ae