fix(exporter): dedup NICs by normalized MAC, fix garbage redis serial fallback

MAC-format mismatches between collector sources (dash vs colon separators)
were preventing duplicate NIC/PCIe entries from merging in the canonical
device dedup pass. Add MAC address normalization and merge devices that
share a normalized MAC before the existing serial/BDF-based dedup runs.

Also fix a bug in the Inspur redis-dump serial fallback parser: when a
field's inline value was the placeholder "N/A", the code incorrectly fell
through to a window-scan fallback that could pick up an unrelated adjacent
Redis key name (e.g. "AssetInfoPCIEMMIOSpace") as a fake serial number.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

internal/exporter/reanimator_converter.go

@@ -237,7 +237,7 @@ func buildDevicesFromLegacy(hw *models.HardwareConfig) []models.HardwareDevice {
 			PartNumber:       pcie.PartNumber,
 			Manufacturer:     pcie.Manufacturer,
 			SerialNumber:     pcie.SerialNumber,
-			MACAddresses:     append([]string(nil), pcie.MACAddresses...),
+			MACAddresses:     normalizeMACAddresses(pcie.MACAddresses),
 			LinkWidth:        pcie.LinkWidth,
 			LinkSpeed:        pcie.LinkSpeed,
 			MaxLinkWidth:     pcie.MaxLinkWidth,
@@ -312,7 +312,7 @@ func buildDevicesFromLegacy(hw *models.HardwareConfig) []models.HardwareDevice {
 			Firmware:         nic.Firmware,
 			PortCount:        nic.PortCount,
 			PortType:         nic.PortType,
-			MACAddresses:     nic.MACAddresses,
+			MACAddresses:     normalizeMACAddresses(nic.MACAddresses),
 			LinkWidth:        nic.LinkWidth,
 			LinkSpeed:        nic.LinkSpeed,
 			MaxLinkWidth:     nic.MaxLinkWidth,
@@ -357,7 +357,157 @@ func buildDevicesFromLegacy(hw *models.HardwareConfig) []models.HardwareDevice {
 	return dedupeCanonicalDevices(all)
 }
 
+// normalizeMACAddress converts a MAC address to a canonical "AA:BB:CC:DD:EE:FF"
+// form regardless of the separator/casing used by the source (colon, dash, dot,
+// or none). Returns "" if the value doesn't contain exactly 12 hex digits.
+func normalizeMACAddress(mac string) string {
+	var hexDigits [12]byte
+	n := 0
+	for i := 0; i < len(mac); i++ {
+		c := mac[i]
+		switch {
+		case c >= '0' && c <= '9', c >= 'a' && c <= 'f', c >= 'A' && c <= 'F':
+			if n == 12 {
+				return ""
+			}
+			hexDigits[n] = c
+			n++
+		}
+	}
+	if n != 12 {
+		return ""
+	}
+	var b strings.Builder
+	b.Grow(17)
+	for i := 0; i < 12; i += 2 {
+		if i > 0 {
+			b.WriteByte(':')
+		}
+		b.WriteByte(hexDigits[i])
+		b.WriteByte(hexDigits[i+1])
+	}
+	return strings.ToUpper(b.String())
+}
+
+// normalizeMACAddresses normalizes each address to canonical form, dropping
+// unparsable entries and de-duplicating while preserving order.
+func normalizeMACAddresses(macs []string) []string {
+	if len(macs) == 0 {
+		return nil
+	}
+	seen := make(map[string]struct{}, len(macs))
+	out := make([]string, 0, len(macs))
+	for _, mac := range macs {
+		nm := normalizeMACAddress(mac)
+		if nm == "" {
+			continue
+		}
+		if _, ok := seen[nm]; ok {
+			continue
+		}
+		seen[nm] = struct{}{}
+		out = append(out, nm)
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return out
+}
+
+// mergeDevicesBySharedMAC merges network-class devices that share at least one
+// normalized MAC address, regardless of their Serial/BDF/slot identity. This
+// runs before the serial/BDF based canonicalKey grouping so that a device with
+// a bogus or mismatched serial/slot (e.g. from a different collector source)
+// still merges with its true duplicate as long as the hardware MAC overlaps.
+func mergeDevicesBySharedMAC(items []models.HardwareDevice) []models.HardwareDevice {
+	if len(items) <= 1 {
+		return items
+	}
+
+	eligible := func(kind string) bool {
+		return kind == models.DeviceKindNetwork || kind == models.DeviceKindPCIe
+	}
+
+	parent := make([]int, len(items))
+	for i := range parent {
+		parent[i] = i
+	}
+	var find func(int) int
+	find = func(x int) int {
+		for parent[x] != x {
+			parent[x] = parent[parent[x]]
+			x = parent[x]
+		}
+		return x
+	}
+	union := func(a, b int) {
+		ra, rb := find(a), find(b)
+		if ra != rb {
+			parent[ra] = rb
+		}
+	}
+
+	macToIndices := make(map[string][]int)
+	for i, item := range items {
+		if !eligible(item.Kind) {
+			continue
+		}
+		for _, mac := range item.MACAddresses {
+			nm := normalizeMACAddress(mac)
+			if nm == "" {
+				continue
+			}
+			macToIndices[nm] = append(macToIndices[nm], i)
+		}
+	}
+	merged := false
+	for _, idxs := range macToIndices {
+		for k := 1; k < len(idxs); k++ {
+			union(idxs[0], idxs[k])
+			merged = true
+		}
+	}
+	if !merged {
+		return items
+	}
+
+	order := make([]int, 0, len(items))
+	groups := make(map[int][]int, len(items))
+	for i := range items {
+		root := find(i)
+		if _, ok := groups[root]; !ok {
+			order = append(order, root)
+		}
+		groups[root] = append(groups[root], i)
+	}
+
+	out := make([]models.HardwareDevice, 0, len(order))
+	for _, root := range order {
+		members := groups[root]
+		if len(members) == 1 {
+			out = append(out, items[members[0]])
+			continue
+		}
+		best := members[0]
+		for _, idx := range members[1:] {
+			if canonicalScore(items[idx]) > canonicalScore(items[best]) {
+				best = idx
+			}
+		}
+		mergedItem := items[best]
+		for _, idx := range members {
+			if idx == best {
+				continue
+			}
+			mergedItem = mergeCanonicalDevice(mergedItem, items[idx])
+		}
+		out = append(out, mergedItem)
+	}
+	return out
+}
+
 func dedupeCanonicalDevices(items []models.HardwareDevice) []models.HardwareDevice {
+	items = mergeDevicesBySharedMAC(items)
 	type scored struct {
 		item  models.HardwareDevice
 		score int