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/server.py

@@ -7,6 +7,7 @@ absolute imports instead of relative imports.
 
 import sys
 import os
+import re
 
 # On Windows with --noconsole (PyInstaller), sys.stdout/stderr are None.
 # They can also be broken file objects in some edge cases.
@@ -47,6 +48,17 @@ if "--version" in sys.argv:
     print(f"voicebox-server {__version__}")
     sys.exit(0)
 
+# Detect backend variant from binary name BEFORE importing backend modules
+# so that env-var guards in app.py (e.g. HSA_OVERRIDE_GFX_VERSION) fire at import time.
+_binary_name = os.path.basename(sys.executable).lower()
+if re.search(r"voicebox-server-rocm(\.exe)?$", _binary_name):
+    os.environ["VOICEBOX_BACKEND_VARIANT"] = "rocm"
+elif re.search(r"voicebox-server-cuda(\.exe)?$", _binary_name):
+    os.environ["VOICEBOX_BACKEND_VARIANT"] = "cuda"
+else:
+    os.environ.setdefault("VOICEBOX_BACKEND_VARIANT", "cpu")
+
+
 import logging
 
 # Set up logging FIRST, before any imports that might fail
@@ -260,16 +272,7 @@ if __name__ == "__main__":
         if args.parent_pid is not None and args.parent_pid <= 0:
             parser.error("--parent-pid must be a positive integer")
 
-        # Detect backend variant from binary name
-        # voicebox-server-cuda → sets VOICEBOX_BACKEND_VARIANT=cuda
-        import os
-        binary_name = os.path.basename(sys.executable).lower()
-        if "cuda" in binary_name:
-            os.environ["VOICEBOX_BACKEND_VARIANT"] = "cuda"
-            logger.info("Backend variant: CUDA")
-        else:
-            os.environ["VOICEBOX_BACKEND_VARIANT"] = "cpu"
-            logger.info("Backend variant: CPU")
+        logger.info(f"Backend variant: {os.environ.get('VOICEBOX_BACKEND_VARIANT', 'cpu').upper()}")
 
         # Register parent watchdog to start after server is fully ready
         if args.parent_pid is not None: