fix: set correct base path for GitHub Pages deployment

base was '/' but site is served at /agent-sh.dev/, causing CSS, favicon,
and navigation links to 404 on GitHub Pages.

Author: avifenesh

astro.config.mjs

@@ -3,5 +3,5 @@ import { defineConfig } from 'astro/config';
 
 export default defineConfig({
   site: 'https://agent-sh.github.io',
-  base: '/',
+  base: '/agent-sh.dev/',
 });