Guard staged prefix stripping

wasm-port/tests/wasm/node/verify_interp_wasm.mjs

@@ -297,11 +297,21 @@ function assertInterpRegressionFileStaging(name, filename, wasmPath) {
   );
 }
 
+function stripInterpIniContextStagingPrefix(name, wasmPath) {
+  const prefix = `/work/interp/${name}/`;
+  assert.equal(
+    wasmPath.startsWith(prefix),
+    true,
+    `interp ${name} staging prefix drift: ${wasmPath}`,
+  );
+  return wasmPath.slice(prefix.length);
+}
+
 function assertInterpIniContextNgcStaging(name, files, plan) {
   assert.deepEqual(
     plan.files
       .filter((file) => file.sourceRel.endsWith(".ngc"))
-      .map((file) => file.wasmPath.replace(`/work/interp/${name}/`, ""))
+      .map((file) => stripInterpIniContextStagingPrefix(name, file.wasmPath))
       .sort(),
     files,
     `interp ${name} staging manifest drift`,