shivam + claude changes

lib/mdx.ts

@@ -10,7 +10,6 @@ export type PostMetadata = {
     description: string;
     slug: string;
     tags?: string[];
-    [key: string]: any;
 };
 
 export type Post = {
@@ -27,8 +26,20 @@ export function getPostSlugs() {
 
 export function getPostBySlug(slug: string): Post {
     const realSlug = slug.replace(/\.mdx$/, '');
+
+    if (/[\/\\]|\.\./.test(realSlug)) {
+        throw new Error(`Invalid slug: ${realSlug}`);
+    }
+
     const fullPath = path.join(postsDirectory, `${realSlug}.mdx`);
-    const fileContents = fs.readFileSync(fullPath, 'utf8');
+
+    let fileContents: string;
+    try {
+        fileContents = fs.readFileSync(fullPath, 'utf8');
+    } catch {
+        throw new Error(`Post not found: ${realSlug}`);
+    }
+
     const { data, content } = matter(fileContents);
 
     return {