canonicalKey used serial_number as the primary merge key for pcie-class
devices (PCIe/GPU/Network), falling back to BDF only when serial was empty.
Multi-port NICs commonly report one serial for the whole physical card
across all of its ports/BDFs (e.g. a dual-port ConnectX-5: same serial,
distinct BDFs 0000:65:00.0/.1, distinct MACs). Keying on serial first
collapsed every port sharing that serial into a single canonical device,
silently dropping all but one port from the export.
BDF now takes priority for pcie-class devices, since it uniquely identifies
one physical PCI function; other device kinds (storage, memory, PSU, etc.)
keep the existing serial-first behavior, which is correct there since a
serial genuinely maps 1:1 to a physical unit for those.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
