feat(ci): add NCCL dependency check with install instructions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/workflows/build-release.yml

@@ -32,6 +32,15 @@ jobs:
           fi
           echo "${HOME}/.cargo/bin" >> "$GITHUB_PATH"
 
+      - name: Check for NCCL
+        run: |
+          if ! ldconfig -p | grep -q libnccl.so.2; then
+            echo "ERROR: libnccl not found. Install with:"
+            echo "  sudo dnf config-manager addrepo --from-repofile=https://developer.download.nvidia.com/compute/cuda/repos/rhel9/x86_64/cuda-rhel9.repo"
+            echo "  sudo dnf --repo=cuda-rhel9-x86_64 install libnccl libnccl-devel"
+            exit 1
+          fi
+
       - name: Clone mistral.rs at tag
         run: |
           git clone --depth 1 --branch "${{ inputs.tag }}" \