fix(pcie): stop misclassifying same-vendor non-GPU devices as GPUs

matchesGPUVendor (sat_overlay.go) matched any PCIe DeviceClass containing
the substring "Controller" instead of the actual GPU classes, so a
same-vendor non-GPU device (e.g. an NVIDIA-branded NIC/storage controller)
with a degraded PCIe link surfaced as a pcie:gpu:<vendor> alarm on the
Hardware Summary/webui.

isGPUDevice (app_format.go) had the same bug via a different path: an
"any NVIDIA-vendor device is a GPU" fallback that could inflate the
"GPU: N x <model>" audit summary line with non-GPU companion devices
(NVSwitch/NVLink bridges, etc).

Both now defer to collector.IsGPUClass (exported from the previously
unexported isGPUClass), the canonical exact-match classifier already used
by amdgpu.go — removing the duplicated/incorrect class checks instead of
reimplementing them. Also dedup two more locally-duplicated classifiers
within webui (which doesn't import collector by convention): NIC-class
matching (pages.go/page_topo.go) and GPU-class matching in
page_validate.go now share one copy per package instead of being
reimplemented per file.

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

audit/internal/webui/page_topo.go

@@ -54,14 +54,11 @@ func topoCard(title, body string) string {
 // instead of importing the package for one classifier).
 // ---------------------------------------------------------------------------
 
-// isNICDeviceClassDev mirrors the classification logic in hwDescribeNIC
-// (pages.go), applied to a single device instead of aggregated counts.
+// isNICDeviceClassDev applies isNICDeviceClass (pages.go) to a single device,
+// with a MAC-address fallback for devices lspci doesn't classify as NIC.
 func isNICDeviceClassDev(dev schema.HardwarePCIeDevice) bool {
-	if dev.DeviceClass != nil {
-		c := strings.ToLower(strings.TrimSpace(*dev.DeviceClass))
-		if c == "ethernetcontroller" || c == "networkcontroller" || strings.Contains(c, "fibrechannel") {
-			return true
-		}
+	if dev.DeviceClass != nil && isNICDeviceClass(*dev.DeviceClass) {
+		return true
 	}
 	return len(dev.MacAddresses) > 0
 }