feat(iso): add rocm-bandwidth-test for AMD GPU burn-in

- Add rocm-bandwidth-test package to ISO
- Add bee user to 'render' group (/dev/kfd, /dev/dri/renderD* access)
- Add rocm-bandwidth-test symlink alongside rocm-smi

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

iso/builder/config/hooks/normal/9000-bee-setup.hook.chroot

@@ -15,7 +15,7 @@ ensure_bee_console_user() {
     mkdir -p /home/bee
     chown -R bee:bee /home/bee
     echo "bee:eeb" | chpasswd
-    usermod -aG sudo,video,input bee 2>/dev/null || true
+    usermod -aG sudo,video,input,render bee 2>/dev/null || true
 }
 
 ensure_bee_console_user
@@ -46,11 +46,13 @@ chmod +x /usr/local/bin/bee-log-run    2>/dev/null || true
 # Reload udev rules
 udevadm control --reload-rules 2>/dev/null || true
 
-# rocm-smi symlink (package installs to /opt/rocm-*/bin/rocm-smi)
-if [ ! -e /usr/local/bin/rocm-smi ]; then
-    smi_path="$(find /opt -path '*/bin/rocm-smi' -type f 2>/dev/null | sort | tail -1)"
-    [ -n "${smi_path}" ] && ln -sf "${smi_path}" /usr/local/bin/rocm-smi
-fi
+# rocm symlinks (packages install to /opt/rocm-*/bin/)
+for tool in rocm-smi rocm-bandwidth-test; do
+    if [ ! -e /usr/local/bin/${tool} ]; then
+        bin_path="$(find /opt -path "*/bin/${tool}" -type f 2>/dev/null | sort | tail -1)"
+        [ -n "${bin_path}" ] && ln -sf "${bin_path}" /usr/local/bin/${tool}
+    fi
+done
 
 # Create export directory
 mkdir -p /appdata/bee/export