fitnes: apply the Fitness v2 design

Ports legacy/Fitnes v2 into the React landing.

- Copy: nav is now Экономика / Оборудование / Программы / Интерьер, every
  CTA reads «Получить консультацию», the hero has one button, a new label
  and new facts.
- Calculator: the average check defaults to 2 500 ₽, and a new investment
  field drives payback and 12-month ROI. Adds the ЭкзоКлиник source note
  and a new disclaimer.
- Constructor: «Состав оборудования», indications on the device cards. The
  CTA stays live with fewer than three devices picked, and the copy points
  to a consultation instead.
- «Юридическая рамка» is replaced by «Форматы размещения» (12 / 24 / 36 м²).
- Lead form: city and club format are dropped; company and email are
  optional. The server schema already treats them as optional.
- Section headings share one compact scale (headingScale + a `slim`
  640px variant), as in the design's v7 rule.

Deliberately kept from the current site rather than the mockup: the
+7 927 789-60-71 number and the callback modal behind the header call
button, both newer than the design.

With Inter substituted into the mockup (it ships no font and falls back to
Arial), every section height matches at 900 and 1440 px. At 375 px the
hero is 6 px shorter because of the existing fluid h1 on phones.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

fitnes/src/components/RequestSection.tsx

@@ -2,7 +2,7 @@ import { ctaChecklist } from '../data/content'
 import { useReveal } from '../hooks/useReveal'
 import { cx } from '../lib/cx'
 import { CheckIcon } from './Icons'
-import { Container, Label, Section } from './Layout'
+import { Container, Label, Section, headingScale } from './Layout'
 import { LeadForm } from './LeadForm'
 
 export function RequestSection({ configuration, commentPrefill }: { configuration: string; commentPrefill: string }) {
@@ -26,7 +26,7 @@ export function RequestSection({ configuration, commentPrefill }: { configuratio
           <div className="grid md:grid-cols-[1.03fr_0.97fr]">
             <div className="p-[clamp(28px,5vw,58px)]">
               <Label>Персональная конфигурация</Label>
-              <h2 className="mb-[20px] max-w-[680px] text-[clamp(36px,5.5vw,66px)] leading-none">
+              <h2 className={cx('mb-[20px] max-w-[680px]', headingScale)}>
                 Подберем индивидуальный комплект оборудования точно под формат вашего клуба.
               </h2>
               <p className="max-w-[610px] text-[16px] text-[#B6C9D4]">