fix(exporter): propagate iommu_group through PCIe export pipeline

IOMMUGroup was added to models.PCIeDevice but never wired into the
converter — missing from Details in buildDevicesFromLegacy, no field
in ReanimatorPCIe, and convertPCIeFromDevices never read it.

Add IOMMUGroup *int to ReanimatorPCIe, propagate through Details,
add intPtrFromDetailMap helper.

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

internal/exporter/reanimator_converter.go

@@ -218,6 +218,9 @@ func buildDevicesFromLegacy(hw *models.HardwareConfig) []models.HardwareDevice {
 		if pcie.HWSlowdown != nil {
 			details = mergeDetailMaps(details, map[string]any{"hw_slowdown": *pcie.HWSlowdown})
 		}
+		if pcie.IOMMUGroup != nil {
+			details = mergeDetailMaps(details, map[string]any{"iommu_group": *pcie.IOMMUGroup})
+		}
 		present := pcie.Present
 		appendDevice(models.HardwareDevice{
 			Kind:             models.DeviceKindPCIe,
@@ -844,6 +847,7 @@ func convertPCIeFromDevices(devices []models.HardwareDevice, collectedAt string)
 			VendorID:               d.VendorID,
 			DeviceID:               d.DeviceID,
 			NUMANode:               d.NUMANode,
+			IOMMUGroup:             intPtrFromDetailMap(d.Details, "iommu_group"),
 			TemperatureC:           temperatureC,
 			PowerW:                 powerW,
 			LifeRemainingPct:       floatFromDetailMap(d.Details, "life_remaining_pct"),
@@ -2119,6 +2123,17 @@ func parseSocketFromSlot(slot string) int {
 	return v
 }
 
+func intPtrFromDetailMap(details map[string]any, key string) *int {
+	if details == nil {
+		return nil
+	}
+	if _, ok := details[key]; !ok {
+		return nil
+	}
+	v := intFromDetailMap(details, key)
+	return &v
+}
+
 func intFromDetailMap(details map[string]any, key string) int {
 	if details == nil {
 		return 0

internal/exporter/reanimator_models.go

@@ -143,6 +143,7 @@ type ReanimatorPCIe struct {
 	VendorID               int                            `json:"vendor_id,omitempty"`
 	DeviceID               int                            `json:"device_id,omitempty"`
 	NUMANode               int                            `json:"numa_node,omitempty"`
+	IOMMUGroup             *int                           `json:"iommu_group,omitempty"`
 	TemperatureC           float64                        `json:"temperature_c,omitempty"`
 	PowerW                 float64                        `json:"power_w,omitempty"`
 	LifeRemainingPct       float64                        `json:"life_remaining_pct,omitempty"`