Restructure web UI navigation into 7 numbered workflow stages

Replace the flat menu (Dashboard, Audit, Validate, Burn, Benchmark,
Tasks, Tools) with a numbered progression that guides engineers through
a logical acceptance workflow:

  Dashboard (landing) → 1. Audit → 2. Check → 3. Load → 4. Speed
  → 5. Endurance → 6. Tools → 7. Settings

Key changes:
- layout.go: numbered nav labels, new hrefs, Tasks removed from nav
  and replaced with a persistent sidebar badge (polls /api/tasks every
  5 s, highlights amber when tasks are active)
- server.go: 301 redirects from /validate→/check, /burn→/load,
  /benchmark→/speed for backward compatibility
- pages.go: dispatch cases for all new routes; old routes kept as
  fallbacks
- page_validate.go: add renderCheck() — non-destructive check page
  with validate-mode tests only (no stress toggle, no targeted-stress/
  targeted-power/pulse cards)
- page_burn.go: add renderLoad() wrapper; update scope alert to
  reference /check instead of /validate
- page_benchmark.go: add renderSpeed() (performance focus) and
  renderEndurance() (stability/overnight focus) wrappers
- page_settings.go: new Settings page with blackbox logging toggle,
  NVIDIA driver reset, and build info
- server_test.go: update five tests to use new route names and
  content expectations

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

audit/internal/webui/pages.go

@@ -24,41 +24,54 @@ func renderPage(page string, opts HandlerOptions) string {
 		body = renderDashboard(opts)
 	case "audit":
 		pageID = "audit"
-		title = "Audit"
+		title = "1. Audit"
 		body = renderAudit()
-	case "validate":
-		pageID = "validate"
-		title = "Validate"
-		body = renderValidate(opts)
-	case "burn":
-		pageID = "burn"
-		title = "Burn"
-		body = renderBurn()
+	case "check":
+		pageID = "check"
+		title = "2. Check"
+		body = renderCheck(opts)
+	case "load":
+		pageID = "load"
+		title = "3. Load"
+		body = renderLoad()
+	case "speed":
+		pageID = "speed"
+		title = "4. Speed"
+		body = renderSpeed(opts)
+	case "endurance":
+		pageID = "endurance"
+		title = "5. Endurance"
+		body = renderEndurance(opts)
+	case "tools":
+		pageID = "tools"
+		title = "6. Tools"
+		body = renderTools()
+	case "settings":
+		pageID = "settings"
+		title = "7. Settings"
+		body = renderSettings(opts)
+	// Legacy routes (redirected at HTTP level in handlePage; these are fallbacks)
+	case "validate", "tests":
+		pageID = "check"
+		title = "2. Check"
+		body = renderCheck(opts)
+	case "burn", "burn-in":
+		pageID = "load"
+		title = "3. Load"
+		body = renderLoad()
 	case "benchmark":
-		pageID = "benchmark"
-		title = "Benchmark"
-		body = renderBenchmark(opts)
+		pageID = "speed"
+		title = "4. Speed"
+		body = renderSpeed(opts)
 	case "tasks":
 		pageID = "tasks"
 		title = "Tasks"
 		body = renderTasks()
-	case "tools":
-		pageID = "tools"
-		title = "Tools"
-		body = renderTools()
-	// Legacy routes kept accessible but not in nav
+	// Hidden pages (not in nav, accessible by direct URL)
 	case "metrics":
 		pageID = "metrics"
 		title = "Live Metrics"
 		body = renderMetrics()
-	case "tests":
-		pageID = "validate"
-		title = "Acceptance Tests"
-		body = renderValidate(opts)
-	case "burn-in":
-		pageID = "burn"
-		title = "Burn-in Tests"
-		body = renderBurn()
 	case "network":
 		pageID = "network"
 		title = "Network"