Fix Alpine setup to patch transformers backend directly

Instead of creating a stub onnxruntime-node module, patch the
@xenova/transformers backend file to skip the onnxruntime-node
import entirely and use only onnxruntime-web.

This prevents the "Cannot read properties of undefined" error
when the library tries to use the Node backend in a Node.js
environment but only has the web backend available.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

scripts/alpine-setup.sh

@@ -1,28 +1,43 @@
 #!/bin/sh
 # Alpine Linux setup script
-# Removes onnxruntime-node to prevent glibc dependency errors
-# The transformers library will fall back to onnxruntime-web (WASM)
+# Patches @xenova/transformers to use onnxruntime-web instead of onnxruntime-node
+# This is required for Alpine Linux (musl libc) compatibility
 
-echo "Removing onnxruntime-node for Alpine Linux compatibility..."
+echo "Configuring Transformers.js for Alpine Linux (WASM backend)..."
 
-# Remove the onnxruntime-node directory
-rm -rf node_modules/onnxruntime-node
+# Patch the ONNX backend selector to always use onnxruntime-web
+ONNX_BACKEND_FILE="node_modules/@xenova/transformers/src/backends/onnx.js"
 
-# Create a stub module so imports don't fail
-mkdir -p node_modules/onnxruntime-node
-cat > node_modules/onnxruntime-node/package.json << 'EOF'
-{
-  "name": "onnxruntime-node",
-  "version": "0.0.0-stub",
-  "main": "index.js",
-  "type": "module"
-}
+if [ -f "$ONNX_BACKEND_FILE" ]; then
+    # Backup original file
+    cp "$ONNX_BACKEND_FILE" "$ONNX_BACKEND_FILE.bak"
+
+    # Replace the backend selection logic to always use ONNX_WEB
+    cat > "$ONNX_BACKEND_FILE" << 'EOF'
+/**
+ * @file Handler file for choosing the correct version of ONNX Runtime, based on the environment.
+ * PATCHED FOR ALPINE LINUX: Always uses onnxruntime-web (WASM backend)
+ * @module backends/onnx
+ */
+
+// Only import onnxruntime-web for Alpine Linux compatibility
+import * as ONNX_WEB from 'onnxruntime-web';
+
+/** @type {import('onnxruntime-web')} The ONNX runtime module. */
+export let ONNX;
+
+export const executionProviders = [
+    'wasm'
+];
+
+// Always use ONNX_WEB (WASM backend) on Alpine Linux
+ONNX = ONNX_WEB.default ?? ONNX_WEB;
 EOF
 
-cat > node_modules/onnxruntime-node/index.js << 'EOF'
-// Stub module for Alpine Linux
-// @xenova/transformers will use onnxruntime-web instead
-export default {};
-EOF
+    echo "✓ Patched @xenova/transformers backend to use WASM"
+else
+    echo "✗ Could not find $ONNX_BACKEND_FILE"
+    exit 1
+fi
 
 echo "✓ Alpine Linux setup complete - WASM backend will be used"