fix(frontend): add tailwind typography plugin for markdown styling

Install @tailwindcss/typography package and configure it in
tailwind.config.js to properly style rendered markdown content.
The prose class now applies correct styles to headings, lists,
code blocks, and other markdown elements.

frontend/tailwind.config.js

@@ -8,5 +8,7 @@ export default {
   theme: {
     extend: {},
   },
-  plugins: [],
+  plugins: [
+    require('@tailwindcss/typography'),
+  ],
 }