Fix KeyStatic: Add server function redirect

Add redirect to route all requests to the Netlify SSR server function.
This enables KeyStatic API routes and GitHub OAuth to work properly.

Co-Authored-By: Claude <noreply@anthropic.com>

netlify.toml

@@ -8,3 +8,9 @@
   for = "/_astro/*"
   [headers.values]
     Cache-Control = "public, max-age=31536000, immutable"
+
+[[redirects]]
+  from = "/*"
+  to = "/.netlify/build/entry.mjs"
+  status = 200
+  force = true