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/VERSIONS

@@ -11,5 +11,6 @@ CUDA_USERSPACE_VERSION=13.0.96-1
 DCGM_VERSION=3.3.9
 ROCM_VERSION=6.3.4
 ROCM_SMI_VERSION=7.4.0.60304-76~22.04
+ROCM_BANDWIDTH_TEST_VERSION=1.4.0.60304-76~22.04
 GO_VERSION=1.24.0
 AUDIT_VERSION=1.0.0