fix: redirect authenticated users away from login, signup, and password pages

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

packages/frontend/src/routes/password/+page.server.ts

@@ -1,4 +1,9 @@
+import { redirect } from "@sveltejs/kit";
+
 export async function load({ locals }) {
+  if (locals.authStatus?.authenticated) {
+    redirect(302, "/me");
+  }
   return {
     authStatus: locals.authStatus,
   };