Let the GPU transform actually run when deploying to a partner

The detection pattern starts with --, so grep parsed it as an option and exited 2; the negation
made the early return always true and every XML was deployed untransformed, keeping the owner's
NVIDIA device UUID on hosts that have no such card.

Plugin/unraid/Partnership/containers.sh

@@ -174,7 +174,12 @@ transform_xml_for_gpu() {
     local src_xml="$1" gpu_type="$2"
 
     # Detect GPU-aware XMLs — new style (--gpus "device=) or old style (--runtime=nvidia)
-    if ! grep -qE '--gpus[[:space:]]+"device=|--runtime=nvidia|NVIDIA_VISIBLE_DEVICES' "$src_xml" 2>/dev/null; then
+    # -- before the pattern is load-bearing: it begins with "--", so without it grep parses the
+    # pattern as an OPTION, exits 2, and the ! makes this branch always true — the function then
+    # returned the XML untransformed every single time, for every GPU type, with 2>/dev/null
+    # swallowing "invalid option". Every container onboarded to a mirror kept the owner NVIDIA
+    # device UUID and could not start on Intel or AMD hardware. Found 2026-08-23.
+    if ! grep -qE -- '--gpus[[:space:]]+"device=|--runtime=nvidia|NVIDIA_VISIBLE_DEVICES' "$src_xml" 2>/dev/null; then
         echo "$src_xml"
         return 0
     fi