enrichPCIeWithNVIDIAData unconditionally overwrote dev.Status after
collectPCIe() had already flagged a Warning/Critical (e.g. PCIe link
speed degraded), so a clean ECC/remap/reset readout silently downgraded
that finding back to OK while leaving the stale ErrorDescription behind.
Add a severity-ordered merge (OK/Unknown < Warning < Critical) shared
via mergeDeviceStatus in contract.go, and route both the NVIDIA status
calculation and the driver-unavailable fallback through it.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
