Convert medical-centre landing to React + Tailwind v4 with amoCRM lead capture

Ports the single-file MedCsFiz page — the medical centre that already runs
physiotherapy and wants the existing room to earn more — to the same
architecture as the fitness and hotel landings: Vite + React 19 + TypeScript +
Tailwind v4 on the client, Express 5 for the API, zod schema shared between the
two.

The original stays in legacy/index.html as the visual reference. Its 4 MB of
inlined CSS, JS and base64 images become 12 asset files (664 KB) plus a bundle
loaded on demand; the two 1.5 MB / 750 KB device PNGs are recompressed to webp.
The page is split into 18 components with all copy moved to src/data/content.ts.

Leads reuse the fitness amoCRM integration: contact lookup by phone in every
Russian spelling, deal in the first stage of pipeline 10980758, account fields
matched automatically with the rest written to a note. Rate limit, honeypot and
a localStorage fallback so a lead survives the CRM being down. Endpoint is
/api/leads/medical-centers-existing-physio; Vite runs on 5173 and the API on
3000.

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

medcenter/src/components/SiteHeader.tsx

@@ -0,0 +1,49 @@
+import logo from '../assets/images/exo-logo.png'
+import { contacts, navLinks } from '../data/content'
+import { ButtonLink, buttonClass, headerSize } from './Button'
+import { PhoneIcon } from './Icons'
+import { Container } from './Layout'
+
+/**
+ * The original ended up with the blurred background painted unconditionally —
+ * the last stylesheet override drops the scroll-dependent variant — so there is
+ * no scroll state to track here.
+ */
+export function SiteHeader() {
+  return (
+    <header className="fixed inset-x-0 top-0 z-[60] bg-navy-deep/[0.92] py-[14px] shadow-[0_12px_42px_rgb(3_20_34/0.18)] backdrop-blur-[18px]">
+      <Container className="flex items-center justify-between gap-[18px]">
+        <a className="inline-flex min-w-0 items-center" href="#top" aria-label="ЭКЗО Групп — наверх">
+          <img
+            alt="ЭКЗО Групп — российские технологии реабилитации"
+            className="block h-auto w-[clamp(172px,20vw,232px)] max-w-full object-contain object-left compact:w-[168px]"
+            src={logo}
+            width={900}
+            height={204}
+          />
+        </a>
+
+        <nav
+          aria-label="Основная навигация"
+          className="hidden items-center gap-[28px] text-[14px] font-[680] text-white/[0.76] lg:flex"
+        >
+          {navLinks.map((link) => (
+            <a key={link.href} href={link.href} className="transition-colors duration-200 hover:text-white">
+              {link.label}
+            </a>
+          ))}
+        </nav>
+
+        <div className="flex shrink-0 items-center gap-[8px]">
+          <a href={contacts.phoneHref} aria-label="Позвонить в Экзо Групп" className={buttonClass('call', undefined, headerSize)}>
+            <PhoneIcon />
+            <span>Звонок</span>
+          </a>
+          <ButtonLink href="#proposal" size={headerSize}>
+            Получить предложение
+          </ButtonLink>
+        </div>
+      </Container>
+    </header>
+  )
+}