Add IPFS HLS streaming and GPU optimizations

- Add IPFSHLSOutput class that uploads segments to IPFS as they're created
- Update streaming task to use IPFS HLS output for distributed streaming
- Add /ipfs-stream endpoint to get IPFS playlist URL
- Update /stream endpoint to redirect to IPFS when available
- Add GPU persistence mode (STREAMING_GPU_PERSIST=1) to keep frames on GPU
- Add hardware video decoding (NVDEC) support for faster video processing
- Add GPU-accelerated primitive libraries: blending_gpu, color_ops_gpu, geometry_gpu
- Add streaming_gpu module with GPUFrame class for tracking CPU/GPU data location
- Add Dockerfile.gpu for building GPU-enabled worker image

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/setup-gpu-droplet.sh

@@ -0,0 +1,108 @@
+#!/bin/bash
+# Setup script for GPU droplet with NVENC support
+# Run as root on a fresh Ubuntu droplet with NVIDIA GPU
+
+set -e
+
+echo "=== ArtDAG GPU Droplet Setup ==="
+
+# 1. System updates
+echo "[1/7] Updating system..."
+apt-get update
+apt-get upgrade -y
+
+# 2. Install NVIDIA drivers (if not already installed)
+echo "[2/7] Checking NVIDIA drivers..."
+if ! command -v nvidia-smi &> /dev/null; then
+    echo "Installing NVIDIA drivers..."
+    apt-get install -y nvidia-driver-535 nvidia-utils-535
+    echo "NVIDIA drivers installed. Reboot required."
+    echo "After reboot, run this script again."
+    exit 0
+fi
+
+nvidia-smi
+echo "NVIDIA drivers OK"
+
+# 3. Install FFmpeg with NVENC support
+echo "[3/7] Installing FFmpeg with NVENC..."
+apt-get install -y ffmpeg
+
+# Verify NVENC
+if ffmpeg -encoders 2>/dev/null | grep -q nvenc; then
+    echo "NVENC available:"
+    ffmpeg -encoders 2>/dev/null | grep nvenc
+else
+    echo "WARNING: NVENC not available. GPU may not support hardware encoding."
+fi
+
+# 4. Install Python and create venv
+echo "[4/7] Setting up Python environment..."
+apt-get install -y python3 python3-venv python3-pip git
+
+VENV_DIR="/opt/artdag-gpu"
+python3 -m venv "$VENV_DIR"
+source "$VENV_DIR/bin/activate"
+
+# 5. Install Python dependencies
+echo "[5/7] Installing Python packages..."
+pip install --upgrade pip
+pip install \
+    numpy \
+    opencv-python-headless \
+    wgpu \
+    httpx \
+    pyyaml \
+    celery[redis] \
+    fastapi \
+    uvicorn
+
+# 6. Clone/update art-dag code
+echo "[6/7] Setting up art-dag code..."
+ARTDAG_DIR="$VENV_DIR/celery"
+if [ -d "$ARTDAG_DIR" ]; then
+    echo "Updating existing code..."
+    cd "$ARTDAG_DIR"
+    git pull || true
+else
+    echo "Cloning art-dag..."
+    git clone https://git.rose-ash.com/art-dag/celery.git "$ARTDAG_DIR" || {
+        echo "Git clone failed. You may need to copy code manually."
+    }
+fi
+
+# 7. Test GPU compute
+echo "[7/7] Testing GPU compute..."
+"$VENV_DIR/bin/python3" << 'PYTEST'
+import sys
+try:
+    import wgpu
+    adapter = wgpu.gpu.request_adapter_sync(power_preference="high-performance")
+    print(f"GPU Adapter: {adapter.info.get('device', 'unknown')}")
+    device = adapter.request_device_sync()
+    print("wgpu device created successfully")
+
+    # Check for NVENC via FFmpeg
+    import subprocess
+    result = subprocess.run(['ffmpeg', '-encoders'], capture_output=True, text=True)
+    if 'h264_nvenc' in result.stdout:
+        print("NVENC H.264 encoder: AVAILABLE")
+    else:
+        print("NVENC H.264 encoder: NOT AVAILABLE")
+    if 'hevc_nvenc' in result.stdout:
+        print("NVENC HEVC encoder: AVAILABLE")
+    else:
+        print("NVENC HEVC encoder: NOT AVAILABLE")
+
+except Exception as e:
+    print(f"Error: {e}")
+    sys.exit(1)
+PYTEST
+
+echo ""
+echo "=== Setup Complete ==="
+echo "Venv: $VENV_DIR"
+echo "Code: $ARTDAG_DIR"
+echo ""
+echo "To activate: source $VENV_DIR/bin/activate"
+echo "To test: cd $ARTDAG_DIR && python -c 'from streaming.backends import get_backend; print(get_backend(\"wgpu\"))'"