feat: русский UI, версии в футере, даты и устойчивость загрузки API

- API: дата старта всегда YYYY-MM-DD; фронт: parseRaceDate без двойного T00:00:00
- GET /health с version из package.json; Vite define __FRONTEND_VERSION__
- Футер с версиями клиента/сервера (BEM), сетка app-shell на три ряда
- AbortController для карточки старта; ретраи GET при 502–504 и понятные ошибки шлюза
- Русские подписи навигации/страниц, lang=ru, без английских фраз в интерфейсе

backend/src/mappers/race.ts

@@ -4,7 +4,7 @@
  */
 export interface RaceRow {
   id: string;
-  race_date: string;
+  race_date: string | Date;
   title: string;
   distance_km: string;
   status: string | null;
@@ -43,11 +43,23 @@ function toISOString(value: Date | string): string {
   return value instanceof Date ? value.toISOString() : String(value);
 }
 
+/** DATE column may arrive as string or Date; API always exposes YYYY-MM-DD for the calendar day. */
+function raceDateToApiValue(value: string | Date): string {
+  if (typeof value === "string") {
+    const m = value.match(/^(\d{4}-\d{2}-\d{2})/);
+    return m ? m[1]! : value;
+  }
+  const y = value.getFullYear();
+  const mo = String(value.getMonth() + 1).padStart(2, "0");
+  const day = String(value.getDate()).padStart(2, "0");
+  return `${y}-${mo}-${day}`;
+}
+
 /** Convert a DB row to the API DTO (camelCase). */
 export function rowToDto(row: RaceRow): RaceDto {
   return {
     id: row.id,
-    date: row.race_date,
+    date: raceDateToApiValue(row.race_date),
     title: row.title,
     distanceKm: parseFloat(row.distance_km),
     status: row.status,

backend/src/routes/health.ts

@@ -1,10 +1,11 @@
 import { Router, Request, Response } from "express";
 import { checkDbConnection } from "../db";
+import { getBackendVersion } from "../version";
 
 const router = Router();
 
 router.get("/health", (_req: Request, res: Response) => {
-  res.json({ status: "ok" });
+  res.json({ status: "ok", version: getBackendVersion() });
 });
 
 router.get("/ready", async (_req: Request, res: Response) => {

backend/src/version.ts

@@ -0,0 +1,14 @@
+import fs from "fs";
+import path from "path";
+
+let cached: string | null = null;
+
+export function getBackendVersion(): string {
+  if (cached) {
+    return cached;
+  }
+  const pkgPath = path.join(__dirname, "..", "package.json");
+  const raw = fs.readFileSync(pkgPath, "utf-8");
+  cached = (JSON.parse(raw) as { version: string }).version;
+  return cached;
+}

backend/test/app.test.ts

@@ -8,6 +8,8 @@ const app = createApp();
 test("GET /health returns ok", async () => {
   const res = await request(app).get("/health").expect(200);
   assert.equal(res.body.status, "ok");
+  assert.equal(typeof res.body.version, "string");
+  assert.ok(res.body.version.length > 0);
 });
 
 test("GET /ready succeeds with mock database", async () => {