add Confidential Computing readiness check + collect nvidia-smi conf-compute -q

New read-only "Check" step reports whether this server can run NVIDIA
Confidential Computing: CPU TEE support (Intel TDX / AMD SEV-SNP, via
dmesg and kvm_amd sysfs params) and GPU firmware CC capability (via
`nvidia-smi conf-compute -q`). Also collect that command's output into
the techdump export bundle.

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

audit/internal/app/app.go

@@ -134,6 +134,7 @@ type satRunner interface {
 	ResetNvidiaGPU(index int) (string, error)
 	RunMemoryAcceptancePack(ctx context.Context, baseDir string, sizeMB, passes int, logFunc func(string)) (string, error)
 	RunStorageAcceptancePack(ctx context.Context, baseDir string, extended bool, logFunc func(string)) (string, error)
+	RunConfidentialComputingCheckPack(ctx context.Context, baseDir string, logFunc func(string)) (string, error)
 	RunCPUAcceptancePack(ctx context.Context, baseDir string, durationSec int, logFunc func(string)) (string, error)
 	ListNvidiaGPUs() ([]platform.NvidiaGPU, error)
 	DetectGPUVendor() string

audit/internal/app/app_packs.go

@@ -206,6 +206,22 @@ func (a *App) RunStorageAcceptancePackResult(baseDir string) (ActionResult, erro
 	return ActionResult{Title: "Storage SAT", Body: satResultBody(path)}, err
 }
 
+func (a *App) RunConfidentialComputingCheckPackCtx(ctx context.Context, baseDir string, logFunc func(string)) (string, error) {
+	if strings.TrimSpace(baseDir) == "" {
+		baseDir = DefaultSATBaseDir
+	}
+	return a.sat.RunConfidentialComputingCheckPack(ctx, baseDir, logFunc)
+}
+
+func (a *App) RunConfidentialComputingCheckPack(baseDir string, logFunc func(string)) (string, error) {
+	return a.RunConfidentialComputingCheckPackCtx(context.Background(), baseDir, logFunc)
+}
+
+func (a *App) RunConfidentialComputingCheckPackResult(baseDir string) (ActionResult, error) {
+	path, err := a.RunConfidentialComputingCheckPack(baseDir, nil)
+	return ActionResult{Title: "Confidential Computing Check", Body: satResultBody(path)}, err
+}
+
 func (a *App) DetectGPUVendor() string {
 	return a.sat.DetectGPUVendor()
 }

audit/internal/app/app_test.go

@@ -243,6 +243,10 @@ func (f fakeSAT) RunStorageAcceptancePack(_ context.Context, baseDir string, _ b
 	return f.runStorageFn(baseDir)
 }
 
+func (f fakeSAT) RunConfidentialComputingCheckPack(_ context.Context, baseDir string, _ func(string)) (string, error) {
+	return "", nil
+}
+
 func (f fakeSAT) RunCPUAcceptancePack(_ context.Context, baseDir string, durationSec int, _ func(string)) (string, error) {
 	if f.runCPUFn != nil {
 		return f.runCPUFn(baseDir, durationSec)