Changes

Lead page: keep Angebot + Vertrag visible, move the rest into a "Mehr" menu

The hero CTA row showed six coloured buttons. Only Angebot and Vertrag stay
visible; a "Mehr" dropdown on the right holds Fragebogen, Prognose, SEPA and
Onboarding (in that order, each with its icon/colour). Closes on outside
click, Escape and after picking an entry; full-width under the buttons on
small screens. The compact icon toolbar at the top is unchanged.