Make remember checkboxes more subtle and checked by default

- Remember checkboxes now default to checked for better user experience
- Reduced visual prominence with smaller size, lighter colors, and lower opacity
- Users get convenience by default while still being able to opt out

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/src/components/login.rs

@@ -20,13 +20,9 @@ pub fn Login(props: &LoginProps) -> Html {
     let error_message = use_state(|| Option::<String>::None);
     let is_loading = use_state(|| false);
     
-    // Remember checkboxes state
-    let remember_server = use_state(|| {
-        LocalStorage::get::<String>("remembered_server_url").is_ok()
-    });
-    let remember_username = use_state(|| {
-        LocalStorage::get::<String>("remembered_username").is_ok()
-    });
+    // Remember checkboxes state - default to checked
+    let remember_server = use_state(|| true);
+    let remember_username = use_state(|| true);
 
     let server_url_ref = use_node_ref();
     let username_ref = use_node_ref();