feat(support-bundle): add PCIe link diagnostics and system logs

- Add full dmesg (was tail -200), kern.log, syslog
- Add /proc/cmdline, lspci -vvv, nvidia-smi -q
- Add per-GPU PCIe link speed/width from sysfs (NVIDIA devices only)

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

audit/internal/app/support_bundle.go

@@ -27,13 +27,27 @@ var supportBundleCommands = []struct {
 	cmd  []string
 }{
 	{name: "system/uname.txt", cmd: []string{"uname", "-a"}},
+	{name: "system/cmdline.txt", cmd: []string{"cat", "/proc/cmdline"}},
 	{name: "system/lsmod.txt", cmd: []string{"lsmod"}},
 	{name: "system/lspci-nn.txt", cmd: []string{"lspci", "-nn"}},
+	{name: "system/lspci-vvv.txt", cmd: []string{"lspci", "-vvv"}},
 	{name: "system/ip-addr.txt", cmd: []string{"ip", "addr"}},
 	{name: "system/ip-route.txt", cmd: []string{"ip", "route"}},
 	{name: "system/mount.txt", cmd: []string{"mount"}},
 	{name: "system/df-h.txt", cmd: []string{"df", "-h"}},
 	{name: "system/dmesg.txt", cmd: []string{"dmesg"}},
+	{name: "system/nvidia-smi-q.txt", cmd: []string{"nvidia-smi", "-q"}},
+	{name: "system/pcie-nvidia-link.txt", cmd: []string{"sh", "-c", `
+for d in /sys/bus/pci/devices/*/; do
+  vendor=$(cat "$d/vendor" 2>/dev/null)
+  [ "$vendor" = "0x10de" ] || continue
+  dev=$(basename "$d")
+  echo "=== $dev ==="
+  for f in current_link_speed current_link_width max_link_speed max_link_width; do
+    printf "  %-22s %s\n" "$f" "$(cat "$d/$f" 2>/dev/null)"
+  done
+done
+`}},
 }
 
 var supportBundleOptionalFiles = []struct {