fix: pcie gen, nccl binary, netconf sudo, boot noise, firmware cleanup

- nvidia collector: read pcie.link.gen.current/max from nvidia-smi instead
  of sysfs to avoid false Gen1 readings when GPU is in ASPM idle state
- build: remove bee-nccl-gpu-stress from rm -f list so shell script from
  overlay is not silently dropped from the ISO
- smoketest: add explicit checks for bee-gpu-burn, bee-john-gpu-stress,
  bee-nccl-gpu-stress, all_reduce_perf
- netconf: re-exec via sudo when not root to fix RTNETLINK/resolv.conf errors
- auto/config: reduce loglevel 7→3 to show clean systemd output on boot
- auto/config: blacklist snd_hda_intel and related audio modules (unused on servers)
- package-lists: remove firmware-intel-sound and firmware-amd-graphics from
  base list; move firmware-amd-graphics to bee-amd variant only
- bible-local: mark memtest ADR resolved, document working solution

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

audit/internal/collector/nvidia_test.go

@@ -6,7 +6,7 @@ import (
 )
 
 func TestParseNVIDIASMIQuery(t *testing.T) {
-	raw := "0, 00000000:65:00.0, GPU-SERIAL-1, 96.00.1F.00.02, 54, 210.33, 0, 5, Not Active\n"
+	raw := "0, 00000000:65:00.0, GPU-SERIAL-1, 96.00.1F.00.02, 54, 210.33, 0, 5, Not Active, 4, 4, 16, 16\n"
 	byBDF, err := parseNVIDIASMIQuery(raw)
 	if err != nil {
 		t.Fatalf("parse failed: %v", err)
@@ -28,6 +28,12 @@ func TestParseNVIDIASMIQuery(t *testing.T) {
 	if gpu.HWSlowdown == nil || *gpu.HWSlowdown {
 		t.Fatalf("hw slowdown: got %v, want false", gpu.HWSlowdown)
 	}
+	if gpu.PCIeLinkGenCurrent == nil || *gpu.PCIeLinkGenCurrent != 4 {
+		t.Fatalf("pcie link gen current: got %v, want 4", gpu.PCIeLinkGenCurrent)
+	}
+	if gpu.PCIeLinkGenMax == nil || *gpu.PCIeLinkGenMax != 4 {
+		t.Fatalf("pcie link gen max: got %v, want 4", gpu.PCIeLinkGenMax)
+	}
 }
 
 func TestNormalizePCIeBDF(t *testing.T) {