Restructure nav to Load/Burn/Benchmark; fix SAA acpidump dependency

- Nav steps 3-5: Load (validate), Burn (burn-in), Benchmark (speed+endurance merged)
- /load now renders validate mode; /burn renders burn-in; /benchmark replaces /speed+/endurance
- Legacy redirects updated: /validate→/load, /burn-in→/burn, /speed+/endurance→/benchmark
- Add acpica_bin/acpidump from SAA 1.5.0 package; required by saa GetDmiInfo (ExitCode 8)
- build.sh copies acpica_bin/acpidump to /usr/local/bin/acpica_bin/ alongside saa

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

audit/internal/webui/pages.go

@@ -33,15 +33,15 @@ func renderPage(page string, opts HandlerOptions) string {
 	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)
+		body = renderValidateStress(opts)
+	case "burn":
+		pageID = "burn"
+		title = "4. Burn"
+		body = renderBurn()
+	case "benchmark":
+		pageID = "benchmark"
+		title = "5. Benchmark"
+		body = renderBenchmark(opts)
 	case "tools":
 		pageID = "tools"
 		title = "Tools"
@@ -52,17 +52,17 @@ func renderPage(page string, opts HandlerOptions) string {
 		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 = "speed"
-		title = "4. Speed"
-		body = renderSpeed(opts)
+		body = renderValidate(opts)
+	case "burn-in":
+		pageID = "burn"
+		title = "4. Burn"
+		body = renderBurn()
+	case "speed", "endurance":
+		pageID = "benchmark"
+		title = "5. Benchmark"
+		body = renderBenchmark(opts)
 	case "tasks":
 		pageID = "tasks"
 		title = "Tasks"