fix: native loader fallback to per-platform sub-package when postinstall is skipped

src_js/lbug_native.js

@@ -8,10 +8,48 @@
 
 const process = require("process");
 const constants = require("constants");
-const join = require("path").join;
+const fs = require("fs");
+const path = require("path");
+const join = path.join;
+
+/**
+ * Resolve the path to the native addon (lbugjs.node).
+ *
+ * Normally the postinstall script (install.js) copies the prebuilt binary
+ * from the per-platform sub-package into this package directory.  However,
+ * environments that skip lifecycle scripts (e.g. `pnpm dlx`, `pnpx`,
+ * `npm install --ignore-scripts`, sandboxed installs) never run install.js,
+ * so the in-package copy is missing even though the prebuilt binary is
+ * present in the per-platform sub-package.  In that case, fall back to
+ * resolving the binary directly from the sub-package using the same logic
+ * install.js uses.
+ */
+function resolveNativeModulePath() {
+  const inPackagePath = join(__dirname, "lbugjs.node");
+  if (fs.existsSync(inPackagePath)) {
+    return inPackagePath;
+  }
+
+  try {
+    const MAIN_PKG_NAME = require(join(__dirname, "package.json")).name;
+    const subPkgName = `${MAIN_PKG_NAME}-${process.platform}-${process.arch}`;
+    const subPkgMain = require.resolve(`${subPkgName}/package.json`, {
+      paths: [__dirname],
+    });
+    const subPkgBinaryPath = path.join(path.dirname(subPkgMain), "lbugjs.node");
+    if (fs.existsSync(subPkgBinaryPath)) {
+      return subPkgBinaryPath;
+    }
+  } catch (e) {
+    // Sub-package not installed (unsupported platform or missing optionalDep);
+    // fall through and let dlopen surface the original error.
+  }
+
+  return inPackagePath;
+}
 
 const lbugNativeModule = { exports: {} };
-const modulePath = join(__dirname, "lbugjs.node");
+const modulePath = resolveNativeModulePath();
 if (process.platform === "linux") {
   process.dlopen(
     lbugNativeModule,