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/shared/lead.ts

@@ -0,0 +1,45 @@
+import { z } from 'zod'
+
+/** Which form on the page produced the lead. Surfaces as an amoCRM tag. */
+export const leadFormIds = ['request'] as const
+export type LeadFormId = (typeof leadFormIds)[number]
+
+export const utmKeys = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_content', 'utm_term'] as const
+
+const optionalText = (max: number) =>
+  z
+    .string()
+    .trim()
+    .max(max)
+    .optional()
+    .transform((v) => (v ? v : undefined))
+
+export const leadSchema = z.object({
+  form: z.enum(leadFormIds),
+  name: z.string().trim().min(1, 'Укажите имя').max(200),
+  phone: z.string().trim().min(5, 'Укажите телефон').max(50),
+  email: z
+    .union([z.email().max(200), z.literal('')])
+    .optional()
+    .transform((v) => (v ? v : undefined)),
+  company: optionalText(200),
+  /** «Состояние кабинета» — one of the select's options, or free text. */
+  cabinet_state: optionalText(200),
+  /** «Основной профиль» — one of the select's options, or free text. */
+  profile: optionalText(200),
+  comment: optionalText(4000),
+  page: optionalText(300),
+  referrer: optionalText(500),
+  // partialRecord, not record: z.record over an enum requires every key.
+  utm: z.partialRecord(z.enum(utmKeys), z.string().max(300)).optional(),
+  /** Honeypot. Bots fill it in; humans never see it. */
+  website: z.string().max(200).optional(),
+})
+
+export type LeadPayload = z.infer<typeof leadSchema>
+/** What the client sends — before zod's optional/empty-string normalisation. */
+export type LeadInput = z.input<typeof leadSchema>
+
+export type LeadResponse =
+  | { ok: true; leadId: number; contactId: number }
+  | { ok: false; error: string; fields?: Record<string, string> }