[Rewrite-Frontend]: Implementing user settings

In the rewrite version of Notangles, currently editing some user settings makes no effect, this is because their upstream components have not been implemented (like the class card component). This issue is created as a remidner to remember implementing these settings logic after their upstreams are completed.

Start in the rewrite frontend by locating the user settings UI and the upstream components it depends on, including the class card component mentioned in the issue. First confirm which settings currently have no effect and which upstreams are incomplete. Done means the affected settings apply their intended changes once those upstream components are available; no files or tests are named, so ask for project guidance before starting.

Written by the indexing model from the issue text.