Fix SATA discovery, add NVLink bridge detection, add infiniband-diags

- storage: add jsonInt64 dual-format unmarshaler to handle lsblk output
  change in util-linux 2.38 (LOG-SEC/PHY-SEC now emitted as JSON
  integers, not quoted strings); fixes SATA disks invisible on Debian 12
- pcie: detect NVLink bridge mezzanine CX-7 cards (Mellanox x2, no host
  net ifaces, DeviceName contains "NVLINK" in lspci -v) and mark them
  with device_class="NVLinkBridge"; escalate PCIe link speed downgrade to
  Critical for these cards (Gen3 on a fixed internal connector = hardware
  fault, not a transient warning)
- pcie: cross-reference nvidia-smi topo to capture NVLink bond counts and
  active status for all NVLink bridge cards
- packages: add infiniband-diags to ISO; provides ibstat required by
  nvidia-fabricmanager-start.sh to enumerate IB devices before FM launch
  (absence causes CUDA_ERROR_SYSTEM_NOT_READY)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/collector/collector.go

@@ -40,6 +40,7 @@ func Run(_ runtimeenv.Mode) schema.HardwareIngestRequest {
 	snap.PCIeDevices = enrichPCIeWithAMD(snap.PCIeDevices)
 	snap.PCIeDevices = enrichPCIeWithPCISerials(snap.PCIeDevices)
 	snap.PCIeDevices = enrichPCIeWithNVIDIA(snap.PCIeDevices)
+	snap.PCIeDevices = enrichNVLinkBridgesWithGPUTopo(snap.PCIeDevices)
 	snap.PCIeDevices = enrichPCIeWithMellanox(snap.PCIeDevices)
 	snap.PCIeDevices = enrichPCIeWithNICTelemetry(snap.PCIeDevices)
 	snap.PCIeDevices = enrichPCIeWithRAIDTelemetry(snap.PCIeDevices)