Changes

Flag-led language switch; move the free-of-charge message under the stock matrix

The language toggle filled its active half with --color-blood-700 — the same red as
the primary "Registrieren" button — so two red elements sat side by side in the
header and the switch competed with the one action that matters. It is now
flag-led: the flag carries the meaning, selection is shown by saturation plus a
neutral tinted background, and red goes back to belonging to the CTA alone.

The DE/EN code stays beside each flag deliberately. A flag denotes a country
rather than a language, and the Union Jack for "English" is a convention rather
than a fact, so the text is what actually disambiguates; both buttons keep their
aria-label and gain a title.

The free-of-charge block moves out of the hero's left column to sit under the
stock matrix, so the reader meets it right after seeing what the product does
rather than beside the headline. Recoloured red to green: red is the blood and
brand colour and made a reassurance read like an alert. Green is the conventional
"no cost" signal and nothing else on the page uses it, so it stands out without
competing. Added as contrast-checked --color-free-* tokens rather than stock
emerald, matching how the rest of the palette is defined.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
 (commit: 992a7b1)