- Drop "Logout" everywhere in the flow: nothing is persisted to the
database until Garmin actually connects, so closing the tab is
already a clean escape hatch -- no separate control needed.
- Display-name step: replace the "Next" button with a small checkmark
icon button next to the input (Enter still submits).
- Garmin credentials step: drop "Previous" (changing the display name
just means quitting and relaunching, since nothing is persisted yet)
and rename "Next" to "Login".
- MFA step: drop "Previous" for the same reason.
- Once Garmin reports success (MFA or not), finish setup immediately
instead of waiting on a "Continue to geniusrun" click.
