Implement native module loading based on platform and architecture; add error handling for unsupported combinations.

Author: sunnylqm

index.js

@@ -1,4 +1,25 @@
-const native = require('node-gyp-build')(__dirname);
+function loadNative() {
+  const platform = process.platform;
+  const arch = process.arch;
+
+  if (platform === 'darwin' && arch === 'arm64') {
+    return require('./prebuilds/darwin-arm64/node-hdiffpatch.node');
+  }
+  if (platform === 'linux' && arch === 'x64') {
+    return require('./prebuilds/linux-x64/node-hdiffpatch.node');
+  }
+  if (platform === 'linux' && arch === 'arm64') {
+    return require('./prebuilds/linux-arm64/node-hdiffpatch.node');
+  }
+
+  const combo = `${platform}-${arch}`;
+  throw new Error(
+    `Unsupported platform/arch: ${combo}. ` +
+      'No prebuilt binary is available for this platform.'
+  );
+}
+
+const native = loadNative();
 
 exports.native = native;