Refactor admin settings page, add UserCard component, and update user management functionality

src/lib/components/UserCard.svelte

@@ -0,0 +1,17 @@
+<script lang="ts">
+  import type { DatabaseUser } from "$lib/server/auth";
+
+  export let user: DatabaseUser;
+</script>
+
+<div class="card w-96 bg-base-100 shadow-xl">
+  <div class="card-body">
+    <h2 class="card-title">{user.first_name} {user.last_name}</h2>
+    <p>{user.username}</p>
+    <p>Last Login: {user.last_login}</p>
+    <p>Created: {user.signup_date}</p>
+    <div class="card-actions justify-end">
+      <button class="btn btn-primary">Edit User</button>
+    </div>
+  </div>
+</div>