refactor(quickstart): replace multi-page wizard with single-page tabbed form

Use GroupedWizardForm from client/wizard to consolidate 6-13 sequential
huh forms into one tabbed interface with 5 groups (Server, Listener,
Pipelines, Build, Notify). Build and Notify are optional collapsible
tabs. Users can navigate freely with Tab/number keys and submit all
config at once with Ctrl+D.

Author: h3zh1