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/server.go

@@ -1424,13 +1424,13 @@ func (h *handler) handlePage(w http.ResponseWriter, r *http.Request) {
 	// Redirect legacy routes to new named pages
 	switch page {
 	case "validate", "tests":
-		http.Redirect(w, r, "/check", http.StatusMovedPermanently)
-		return
-	case "burn", "burn-in":
 		http.Redirect(w, r, "/load", http.StatusMovedPermanently)
 		return
-	case "benchmark":
-		http.Redirect(w, r, "/speed", http.StatusMovedPermanently)
+	case "burn-in":
+		http.Redirect(w, r, "/burn", http.StatusMovedPermanently)
+		return
+	case "speed", "endurance":
+		http.Redirect(w, r, "/benchmark", http.StatusMovedPermanently)
 		return
 	}
 	body := renderPage(page, h.opts)