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>

iso/builder/build.sh

@@ -1483,6 +1483,16 @@ for tool in storcli64 sas2ircu sas3ircu arcconf ssacli saa; do
     fi
 done
 
+# saa requires acpica_bin/acpidump relative to its own location
+if [ -f "${VENDOR_DIR}/acpica_bin/acpidump" ]; then
+    mkdir -p "${OVERLAY_STAGE_DIR}/usr/local/bin/acpica_bin"
+    cp "${VENDOR_DIR}/acpica_bin/acpidump" "${OVERLAY_STAGE_DIR}/usr/local/bin/acpica_bin/acpidump"
+    chmod +x "${OVERLAY_STAGE_DIR}/usr/local/bin/acpica_bin/acpidump" || true
+    echo "vendor tool: acpica_bin/acpidump (included)"
+else
+    echo "vendor tool: acpica_bin/acpidump (not found, skipped)"
+fi
+
 # --- NVIDIA kernel modules and userspace libs ---
 if [ "$BEE_GPU_VENDOR" = "nvidia" ]; then
     run_step "build NVIDIA ${NVIDIA_DRIVER_VERSION} modules" "40-nvidia-module" \