feat(nccl): add nccl-tests all_reduce_perf for GPU bandwidth testing

- Dockerfile: install cuda-nvcc-13-0 from NVIDIA repo for compilation
- build-nccl-tests.sh: downloads libnccl-dev for nccl.h, builds all_reduce_perf
- build.sh: runs nccl-tests build, injects binary into /usr/local/bin/
- platform: RunNCCLTests() auto-detects GPU count, runs all_reduce_perf
- TUI: NCCL bandwidth test entry in Burn-in Tests screen [N] hotkey

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

audit/internal/tui/screen_burn_in.go

@@ -8,12 +8,13 @@ import (
 )
 
 const (
-	burnCurGPUStress = 0
-	burnCurModeQuick = 1
-	burnCurModeStd   = 2
-	burnCurModeExpr  = 3
-	burnCurRun       = 4
-	burnCurTotal     = 5
+	burnCurGPUStress  = 0
+	burnCurModeQuick  = 1
+	burnCurModeStd    = 2
+	burnCurModeExpr   = 3
+	burnCurRun        = 4
+	burnCurNCCLTests  = 5
+	burnCurTotal      = 6
 )
 
 func (m model) enterBurnInTests() (tea.Model, tea.Cmd) {
@@ -48,9 +49,13 @@ func (m model) updateBurnInTests(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			return m.burnRunSelected()
 		case burnCurModeQuick, burnCurModeStd, burnCurModeExpr:
 			m.burnMode = m.burnCursor - burnCurModeQuick
+		case burnCurNCCLTests:
+			return m.burnRunNCCL()
 		}
 	case "f", "F", "r", "R":
 		return m.burnRunSelected()
+	case "n", "N":
+		return m.burnRunNCCL()
 	case "1":
 		m.burnMode = 0
 	case "2":
@@ -70,6 +75,13 @@ func (m model) burnRunSelected() (tea.Model, tea.Cmd) {
 	return m.hcRunFanStress()
 }
 
+func (m model) burnRunNCCL() (tea.Model, tea.Cmd) {
+	m.pendingAction = actionRunNCCLTests
+	m.screen = screenConfirm
+	m.cursor = 0
+	return m, nil
+}
+
 func renderBurnInTests(m model) string {
 	var b strings.Builder
 
@@ -110,8 +122,15 @@ func renderBurnInTests(m model) string {
 	}
 	fmt.Fprintf(&b, "%s[ RUN SELECTED [R] ]\n", pfx)
 
+	fmt.Fprintln(&b)
+	pfx = "  "
+	if m.burnCursor == burnCurNCCLTests {
+		pfx = "> "
+	}
+	fmt.Fprintf(&b, "%s[ NCCL BANDWIDTH TEST [N] ]         (all_reduce_perf, NVLink/PCIe bandwidth)\n", pfx)
+
 	fmt.Fprintln(&b)
 	fmt.Fprintln(&b, "─────────────────────────────────────────────────────────────────")
-	fmt.Fprint(&b, "[↑↓] move  [space/enter] select  [1/2/3] mode  [R/F] run  [Esc] back")
+	fmt.Fprint(&b, "[↑↓] move  [space/enter] select  [1/2/3] mode  [R/F] run  [N] nccl  [Esc] back")
 	return b.String()
 }