fix: add missing file

File missing from previous commit

src/backend/src/kernel/modutil.js

@@ -0,0 +1,59 @@
+const fs = require('fs').promises;
+const path = require('path');
+
+async function prependToJSFiles(directory, snippet) {
+    const jsExtensions = new Set(['.js', '.cjs', '.mjs']);
+
+    async function processDirectory(dir) {
+        try {
+            const entries = await fs.readdir(dir, { withFileTypes: true });
+            const promises = [];
+
+            for (const entry of entries) {
+                const fullPath = path.join(dir, entry.name);
+
+                if (entry.isDirectory()) {
+                    // Skip common directories that shouldn't be modified
+                    if (!shouldSkipDirectory(entry.name)) {
+                        promises.push(processDirectory(fullPath));
+                    }
+                } else if (entry.isFile() && jsExtensions.has(path.extname(entry.name))) {
+                    promises.push(prependToFile(fullPath, snippet));
+                }
+            }
+
+            await Promise.all(promises);
+        } catch (error) {
+            throw new Error(`error processing directory ${dir}`, {
+                cause: error,
+            });
+        }
+    }
+
+    function shouldSkipDirectory(dirName) {
+        const skipDirs = new Set([
+            'node_modules',
+        ]);
+        if ( skipDirs.has(dirName) ) return true;
+        if ( dirName.startsWith('.') ) return true;
+        return false;
+    }
+
+    async function prependToFile(filePath, snippet) {
+        try {
+            const content = await fs.readFile(filePath, 'utf8');
+            const newContent = snippet + content;
+            await fs.writeFile(filePath, newContent, 'utf8');
+        } catch (error) {
+            throw new Error(`error processing file ${filePath}`, {
+                cause: error,
+            });
+        }
+    }
+
+    await processDirectory(directory);
+}
+
+module.exports = {
+    prependToJSFiles
+};