feat(windows): Native AMD ROCm GPU Acceleration (Resolves #531) (#538)

* feat(windows): add native ROCm support for AMD GPUs

Implements native ROCm architecture for Windows.

- Adds backend build pipeline for voicebox-server-rocm.exe

- Detects AMD GPUs dynamically and routes PyTorch allocations

- Adds automatic download and update logic for ROCm dependencies

- Refactors UI in GpuPage.tsx and GpuAcceleration.tsx to add AMD flows

- Fixes 'Switch to CPU' lock on Windows via Tauri backend_override state

- Resolves PyInstaller/rocm_sdk UnboundLocalError silent crashes

- Resolves Numba/NumPy 2.x incompatibilities during Qwen3-TTS load

- Resolves HF_HUB_OFFLINE Catch-22 for CustomVoice processor caching

* fix(rocm): host libs archive under the app release tag, drop offline-load regression

Align the ROCm libs download with the CUDA pattern: both the server core and
the libs archive are published under the app-version release tag, with the libs
content version encoded in the filename only. The previous code fetched libs
from a separate rocm7.2-v1 tag, which disagreed with the download test.

Also revert the unrelated Qwen CustomVoice changes that wrapped model loading in
force_offline_if_cached (not imported — a NameError on load for every platform)
and re-added a Base-model cache gate. The inference-path offline guard was
deliberately removed previously.

* feat(rocm): gate download on AMD detection and persist the backend variant

The ROCm download section now only shows when the backend reports an AMD GPU on
Windows (new supports_rocm health field, backed by the memoized
is_amd_gpu_windows detection that was previously unused), or when ROCm is already
downloaded/active.

Make the backend override honor a pinned variant: set_backend_override persists
the choice to disk so it survives an app restart, start_server reads it back,
and a cuda/rocm pin now actually selects that variant instead of always
preferring ROCm. A stale pin to a deleted backend self-heals to the default
order rather than forcing CPU. Add the web no-op stub for the new method.

* chore(rocm): drop incomplete vitest harness for the unused GpuAcceleration component

GpuAcceleration.tsx is not routed anywhere (GpuPage is the live settings view),
and the added vitest setup referenced testing-library/vitest deps that were not
in the lockfile, breaking the web typecheck. Remove the dead component's test
and its scaffolding to keep this PR scoped to the ROCm feature.

* ci(rocm): add ROCm release-artifact pipeline

Mirror the CUDA packaging path for ROCm so the runtime download has artifacts to
fetch. scripts/package_rocm.py splits the PyInstaller --rocm onedir into
voicebox-server-rocm.tar.gz (core) + rocm-libs-rocm7.2-v1.tar.gz (AMD runtime:
HIP DLLs, rocBLAS Tensile data, MIOpen kernel DBs) + rocm-libs.json, matching
the names services/rocm.py expects, both under the app-version release tag.

The new build-rocm-windows job in release.yml builds on windows-latest/cp312 and
lets build_binary.py --rocm pull the official AMD Radeon wheels.

The file classifier can't be validated against a real AMD build on CI, so it has
unit coverage (test_package_rocm.py) against a synthetic onedir layout. The
prefixes/dir markers may need a tweak after the first real build on AMD
hardware — the packager hard-fails loudly if it classifies zero ROCm files.

---------

Co-authored-by: Jamie Pine <[email protected]>

backend/utils/platform_detect.py

@@ -3,19 +3,72 @@ Platform detection for backend selection.
 """
 
 import platform
+import subprocess
+from functools import lru_cache
 from typing import Literal
 
 
 def is_apple_silicon() -> bool:
     """
     Check if running on Apple Silicon (arm64 macOS).
-    
+
     Returns:
         True if on Apple Silicon, False otherwise
     """
     return platform.system() == "Darwin" and platform.machine() == "arm64"
 
 
+@lru_cache(maxsize=1)
+def is_amd_gpu_windows() -> bool:
+    """
+    Check if the primary GPU on Windows is an AMD Radeon card.
+
+    Uses WMI to query Win32_VideoController, with a fallback to
+    torch.cuda.get_device_name(0) if WMI is unavailable.  This is
+    useful for deciding whether the ROCm backend is appropriate.
+
+    Result is cached since it shells out to PowerShell and the GPU
+    does not change at runtime — safe to call from the health path.
+
+    Returns:
+        True if an AMD GPU is detected on Windows, False otherwise.
+    """
+    if platform.system() != "Windows":
+        return False
+
+    # Primary method: WMI query for AMD adapters
+    try:
+        result = subprocess.run(
+            [
+                "powershell",
+                "-Command",
+                "Get-CimInstance Win32_VideoController | "
+                "Where-Object {$_.AdapterCompatibility -like '*AMD*'} | "
+                "Measure-Object | Select-Object -ExpandProperty Count",
+            ],
+            capture_output=True,
+            text=True,
+            check=True,
+        )
+        if int(result.stdout.strip()) > 0:
+            return True
+    except Exception:
+        pass
+
+    # Fallback: torch.cuda.get_device_name(0) (works for ROCm/HIP too)
+    try:
+        import torch
+
+        if torch.cuda.is_available():
+            name = torch.cuda.get_device_name(0)
+            if "Radeon" in name or "AMD" in name:
+                return True
+    except Exception:
+        pass
+
+    return False
+
+
 def get_backend_type() -> Literal["mlx", "pytorch"]:
     """
     Detect the best backend for the current platform.