refactor(audit): rename Fan Stress Test → GPU Platform Stress Test

Update all user-facing strings in TUI and ActionResult title.
Internal identifiers (types, functions, file name) unchanged.

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

audit/internal/app/app.go

@@ -505,7 +505,7 @@ func (a *App) RunFanStressTestResult(ctx context.Context, opts platform.FanStres
 	if err != nil && err != context.Canceled {
 		body += "\nERROR: " + err.Error()
 	}
-	return ActionResult{Title: "Fan Stress Test", Body: body}, err
+	return ActionResult{Title: "GPU Platform Stress Test", Body: body}, err
 }
 
 // formatFanStressResult formats the summary.txt from a fan-stress run, including

audit/internal/tui/forms.go

@@ -140,7 +140,7 @@ func (m model) updateConfirm(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 				pollSATProgress("gpu-amd", since),
 			)
 		case actionRunFanStress:
-			m.busyTitle = "Fan Stress Test"
+			m.busyTitle = "GPU Platform Stress Test"
 			m.progressPrefix = "fan-stress"
 			m.progressSince = time.Now()
 			m.progressLines = nil

audit/internal/tui/screen_health_check.go

@@ -317,11 +317,11 @@ func renderHealthCheck(m model) string {
 		if m.hcCursor == hcCurFanStress {
 			pfx = "> "
 		}
-		fmt.Fprintf(&b, "%s[ FAN STRESS TEST [F] ]   (thermal cycling, fan lag, throttle check)\n", pfx)
+		fmt.Fprintf(&b, "%s[ GPU PLATFORM STRESS TEST [F] ]   (thermal cycling, fan lag, throttle check)\n", pfx)
 	}
 
 	fmt.Fprintln(&b)
 	fmt.Fprintln(&b, "─────────────────────────────────────────────────────────────────")
-	fmt.Fprint(&b, "[↑↓] move  [space/enter] toggle  [letter] single test  [R] run all  [F] fan stress  [Esc] back")
+	fmt.Fprint(&b, "[↑↓] move  [space/enter] toggle  [letter] single test  [R] run all  [F] gpu stress  [Esc] back")
 	return b.String()
 }

audit/internal/tui/types.go

@@ -191,7 +191,7 @@ func (m model) confirmBody() (string, string) {
 		return "AMD GPU test", "Run AMD GPU diagnostic pack (rocm-smi)?"
 	case actionRunFanStress:
 		modes := []string{"Quick (2×2min)", "Standard (2×5min)", "Express (2×10min)"}
-		return "Fan Stress Test", "Two-phase GPU thermal cycling test.\n" +
+		return "GPU Platform Stress Test", "Two-phase GPU thermal cycling test.\n" +
 			"Monitors fans, temps, power — detects throttling.\n" +
 			"Mode: " + modes[m.hcMode] + "\n\nAll NVIDIA GPUs will be stressed."
 	default: