feat(audio-cpp): add ROCm backend image

The pinned audio.cpp revision supports HIP, but LocalAI neither builds a ROCm image nor accepts its backend option. AMD hosts therefore fall back to the CPU image.

Build and publish the HIP variant, connect it to AMD capability selection, and accept both upstream HIP names.

Assisted-by: Codex:gpt-5
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

.github/backend-matrix.yml

@@ -3234,9 +3234,10 @@ include:
   # consumed. Same reason CUDA needs its toolkit in base-image rather than in a
   # builder image: this is the ds4 shape, not the llama-cpp one.
   #
-  # No ROCm entry: upstream has no HIP configuration. No CUDA arm64 or L4T
-  # entry: upstream documents and validates CUDA on x86 only. Darwin/Metal is in
-  # the includeDarwin matrix below, built by scripts/build/audio-cpp-darwin.sh.
+  # ROCm uses upstream's HIP backend and the project-wide ROCm 7.2.1 base. No
+  # CUDA arm64 or L4T entry: upstream documents and validates CUDA on x86 only.
+  # Darwin/Metal is in the includeDarwin matrix below, built by
+  # scripts/build/audio-cpp-darwin.sh.
   #
   # No vulkan entry either, though Dockerfile.audio-cpp and the backend Makefile
   # both handle BUILD_TYPE=vulkan for local builds. Every other vulkan backend
@@ -3304,6 +3305,19 @@ include:
     dockerfile: "./backend/Dockerfile.audio-cpp"
     context: "./"
     ubuntu-version: '2404'
+  - build-type: 'hipblas'
+    cuda-major-version: ""
+    cuda-minor-version: ""
+    platforms: 'linux/amd64'
+    tag-latest: 'auto'
+    tag-suffix: '-gpu-rocm-hipblas-audio-cpp'
+    runs-on: 'ubuntu-latest'
+    base-image: "rocm/dev-ubuntu-24.04:7.2.1"
+    skip-drivers: 'false'
+    backend: "audio-cpp"
+    dockerfile: "./backend/Dockerfile.audio-cpp"
+    context: "./"
+    ubuntu-version: '2404'
   - build-type: ''
     cuda-major-version: ""
     cuda-minor-version: ""