Fix installer and hardware detection issues for PR #4720

- Fix empty _tri_arg passed to uv pip install in Radeon path (causes
  "Empty field is not allowed for PEP508" error)
- Fix Radeon fallback: use ROCm index instead of CPU-only when
  repo.radeon.com is unreachable (TORCH_INDEX_URL already has ROCm)
- Use $TORCH_CONSTRAINT in fallback paths instead of hardcoded strings
- Fix _pick_radeon_wheel: relax suffix to match manylinux_2_28_x86_64
  wheels (AMD Radeon repo does not use bare linux_x86_64 platform tag)
- Fix IS_ROCM export: use __getattr__ so callers always see the live
  value after detect_hardware() runs
- Fix apply_gpu_ids: set HIP_VISIBLE_DEVICES and ROCR_VISIBLE_DEVICES
  on ROCm so _get_parent_visible_gpu_spec picks up narrowed GPU set
- Fix _parse_memory_mb: distinguish GB (1000 MB) from GiB (1024 MiB)
- Add amd-smi version as a fallback in _detect_rocm_version
- Fix trailing whitespace and missing newline at EOF in install.sh

studio/install_python_stack.py

@@ -59,6 +59,25 @@ def _detect_rocm_version() -> tuple[int, int] | None:
         except Exception:
             pass
 
+    # Try amd-smi version (outputs "... | ROCm version: X.Y.Z")
+    amd_smi = shutil.which("amd-smi")
+    if amd_smi:
+        try:
+            result = subprocess.run(
+                [amd_smi, "version"],
+                stdout = subprocess.PIPE,
+                stderr = subprocess.DEVNULL,
+                text = True,
+                timeout = 5,
+            )
+            if result.returncode == 0:
+                import re
+                m = re.search(r"ROCm version:\s*(\d+)\.(\d+)", result.stdout)
+                if m:
+                    return int(m.group(1)), int(m.group(2))
+        except Exception:
+            pass
+
     # Try hipconfig --version (outputs bare version like "6.3.21234.2")
     hipconfig = shutil.which("hipconfig")
     if hipconfig: