fix(install): harden AMD ROCm GPU detection for multi-GPU and env-filtered setups

The previous rocminfo awk pattern could miss discrete GPUs on machines
where HIP_VISIBLE_DEVICES/ROCR_VISIBLE_DEVICES is used to mask an
integrated GPU — the env vars filter rocminfo output but may not
propagate into the install script subprocess, causing detection to
fail entirely.

Two changes:
- Tighten rocminfo pattern from /gfx[0-9]/ && !/gfx000/ to
  /gfx[1-9][0-9]/ — simpler and correctly excludes the CPU agent
  (gfx000) without a negative lookahead
- Add sysfs KFD topology fallback: reads
  /sys/class/kfd/kfd/topology/nodes/*/gpu_id which is a kernel-level
  view unaffected by HIP_VISIBLE_DEVICES or ROCR_VISIBLE_DEVICES

Fixes detection failure reported in Discord by Chains (gfx1201 + iGPU
machine where env var exclusion of the iGPU caused rocminfo to return
no usable device).

install.sh

@@ -1478,15 +1478,21 @@ _find_no_torch_runtime() {
 
 # ── AMD ROCm GPU detection helper ──
 # Returns 0 (true) if an actual AMD GPU is present, 1 (false) otherwise.
-# Checks rocminfo for gfx[1-9]* (excludes gfx000 CPU agent) and
-# amd-smi list for GPU data rows (excludes header-only output).
+# Checks rocminfo for gfx[1-9][0-9]+ (excludes gfx000 CPU agent),
+# amd-smi list for GPU data rows, and falls back to sysfs KFD topology
+# which is env-var-independent (works even when HIP_VISIBLE_DEVICES or
+# ROCR_VISIBLE_DEVICES hides devices from rocminfo/amd-smi).
 _has_amd_rocm_gpu() {
     if command -v rocminfo >/dev/null 2>&1 && \
-       rocminfo 2>/dev/null | awk '/Name:[[:space:]]*gfx[0-9]/ && !/Name:[[:space:]]*gfx000/{found=1} END{exit !found}'; then
+       rocminfo 2>/dev/null | awk '/Name:[[:space:]]*gfx[1-9][0-9]/{found=1} END{exit !found}'; then
         return 0
     elif command -v amd-smi >/dev/null 2>&1 && \
          amd-smi list 2>/dev/null | awk '/^GPU[[:space:]]*[:\[][[:space:]]*[0-9]/{ found=1 } END{ exit !found }'; then
         return 0
+    elif [ -e /dev/kfd ] && \
+         awk '/gpu_id/{ if ($2+0 > 0) found=1 } END{ exit !found }' \
+             /sys/class/kfd/kfd/topology/nodes/*/gpu_id 2>/dev/null; then
+        return 0
     fi
     return 1
 }