fix: persist setup wizard choice commits

[anandpant]

Summary

• move setup choice handling out of OpenTUI tab_select and into the wizard keyboard flow so the left pane and step progression stay in sync
• add direct numeric shortcuts for visible choices and broader submit-key handling for terminal variance
• add unit coverage for the new setup key helpers

Testing

• bun run check
• bun run typecheck
• bun test
• bun run build
• npm pack --pack-destination .memory/release-check