Use React Router Form for save-changes submission

[tayloraj10]

Use React Router Form for save-changes submission

Problem

The "Save changes" button on the review detail page was a plain <Button onClick={...}>, unlike the approve/reject buttons on the same page which already use <Form>. This inconsistency meant "Save changes" lacked proper submit semantics (Enter-to-submit, pending state via native form submission, progressive enhancement). Separately, the logout route performed its sign-out mutation from a loader (i.e. a GET request), which is semantically incorrect since GET requests shouldn't have side effects like signing a user out. The FormEvent type used in the save handler was also deprecated.

Solution

• Converted the "Save changes" button to submit via a <fetcher.Form onSubmit>, matching the pattern already used for approve/reject. The payload is still a nested object rather than flat fields, so it's serialized and sent as JSON through fetcher.submit inside the onSubmit handler (with event.preventDefault()), but it's now wired to a real form element.
• Replaced the deprecated FormEvent type with SubmitEvent in the save handler.
• Converted logout from a loader (GET) to an action (POST): the loader now just redirects to / if hit directly via GET, and the actual sign-out mutation lives in the action.
• Updated the sidebar logout link from a <Link> to a <Form method="post" action="/logout"> with a submit button styled to match the original link.

Reference

N/A

Screenshots

N/A (no visual changes — logout button and save button retain their existing appearance/styling)

Checklist

• Changes have been tested locally
• Changes have been self-reviewed