feat: ability to update blog

frontend/src/utils/BlogViewer.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useState } from "react";
-import { useParams } from "react-router-dom";
+import { useNavigate, useParams } from "react-router-dom";
 import { API_URL } from "./constants";
 import type { Blog } from "./types";
 import Markdown from "react-markdown";
@@ -11,6 +11,8 @@ import "../styles/markdown.css";
 export function BlogViewer() {
   const { slug } = useParams<{ slug: string }>();
   const [blog, setBlog] = useState<Blog | null>(null);
+  const navigate = useNavigate();
+  const me = localStorage.getItem("user_id");
 
   useEffect(() => {
     if (!slug) return;
@@ -20,12 +22,20 @@ export function BlogViewer() {
       .catch((err) => console.error(err));
   }, [slug]);
 
-  if (!blog) {
-    return <p>Loading...</p>;
-  }
+  if (!blog) return <p>Loading…</p>;
+
+  const isAuthor = me === String(blog.author_id);
 
   return (
     <div className="max-w-2xl mx-auto py-10 space-y-6">
+      {isAuthor && (
+        <button
+          onClick={() => navigate(`/blog/${slug}/edit`)}
+          className="px-4 py-2 bg-blue-600 text-white rounded hover:bg-blue-700"
+        >
+          Edit this post
+        </button>
+      )}
       <h1 className="text-3xl font-bold">{blog.title.toUpperCase()}</h1>
       <p className="text-sm text-gray-500">By User {blog.author_id}</p>
       <p className="italic text-gray-600 dark:text-gray-400">