fix(inventory): read GPU model from device field, not vendor field

`lspci -D -mm -nn` prefixes every line with the PCI address as a bare
token before the three quoted class/vendor/device fields, so the
device name sits at fields[3] — not fields[2], which is the vendor.
The probe was indexing [2] and recording every GPU's model as its
vendor string ("Intel Corporation" instead of "Alder Lake-N [UHD
Graphics]"), which made every SpecValidate mismatch on real hosts
once the expected spec named the device.

Extract the per-line parse into parseLspciMMLine, handle both the
modern -D layout (addr + class/vendor/device) and the legacy
layout without an address prefix (class/vendor/device), and cover
both paths plus the non-GPU-class skip in inventory_test.go.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

agent/probes/inventory.go

@@ -522,38 +522,7 @@ func GPUs(log Logger) []spec.GPUSpec {
 	}
 	var gpus []spec.GPUSpec
 	for _, line := range strings.Split(string(out), "\n") {
-		low := strings.ToLower(line)
-		if !strings.Contains(low, "vga compatible controller") &&
-			!strings.Contains(low, "3d controller") {
-			continue
-		}
-		// With -D the first quoted field is the PCI address.
-		fields := splitQuoted(line)
-		if len(fields) < 3 {
-			continue
-		}
-		// -D -mm emits the address as the first non-quoted token.
-		// splitQuoted strips unquoted whitespace, so the address is
-		// indexed at 0 and the quoted class/vendor/device follow.
-		// On older lspci the first field is the slot in quotes instead;
-		// cover both: if fields[0] doesn't look like an address, strip
-		// it from the space-separated prefix.
-		addr := ""
-		if pciAddrRE.MatchString(fields[0]) {
-			addr = fields[0]
-		} else if i := strings.IndexByte(line, '"'); i > 0 {
-			prefix := strings.TrimSpace(line[:i])
-			if pciAddrRE.MatchString(prefix) {
-				addr = prefix
-			}
-		}
-		model := stripPCIID(fields[2])
-		if !pciAddrRE.MatchString(fields[0]) {
-			// With no -D support the device is at [1], model at [2]: same
-			// as old code path. Keep existing behavior.
-			model = stripPCIID(fields[2])
-		}
-		model = sanitizeASCII(model)
+		addr, model := parseLspciMMLine(line)
 		if model == "" {
 			continue
 		}
@@ -572,6 +541,46 @@ func GPUs(log Logger) []spec.GPUSpec {
 
 var pciAddrRE = regexp.MustCompile(`^[0-9a-fA-F]{4}:[0-9a-fA-F]{2}:[0-9a-fA-F]{2}\.[0-9a-fA-F]$`)
 
+// parseLspciMMLine extracts the PCI address and sanitized device-model
+// string from one line of `lspci -D -mm -nn` output.
+//
+// With -D the line begins with a bare PCI address token followed by
+// three quoted fields in the order class / vendor / device, so after
+// splitQuoted the address is at fields[0] and the device name lives at
+// fields[3]. Older lspci without -D emits only the three quoted
+// fields: class / vendor / device, putting the device at fields[2].
+// Both layouts are accepted; VGA and 3D-controller classes are the
+// only ones returned (keeps non-GPU PCI entries from slipping in).
+//
+// Returns ("", "") for lines that don't match a GPU class or whose
+// model sanitizes to empty.
+func parseLspciMMLine(line string) (addr, model string) {
+	low := strings.ToLower(line)
+	if !strings.Contains(low, "vga compatible controller") &&
+		!strings.Contains(low, "3d controller") {
+		return "", ""
+	}
+	fields := splitQuoted(line)
+	if len(fields) < 3 {
+		return "", ""
+	}
+	modelIdx := 2
+	if pciAddrRE.MatchString(fields[0]) {
+		addr = fields[0]
+		modelIdx = 3
+	} else if i := strings.IndexByte(line, '"'); i > 0 {
+		prefix := strings.TrimSpace(line[:i])
+		if pciAddrRE.MatchString(prefix) {
+			addr = prefix
+		}
+	}
+	if modelIdx >= len(fields) {
+		return "", ""
+	}
+	model = sanitizeASCII(stripPCIID(fields[modelIdx]))
+	return addr, model
+}
+
 // parseLspciVerbose pulls the largest prefetchable memory region (VRAM)
 // in GiB and the "Kernel driver in use" name from an lspci -vv block.
 // The memory line looks like: "Memory at ... (64-bit, prefetchable) [size=8G]"