Stage 17 round 6 (#13/About): About screen content + app version from git describe

- About screen: prominent localized title (Scrabble / Эрудит (Скрэббл)), a rules link
  (en/ru Wikipedia), and the Random-game / Game-with-friends sections; copy lives in a
  shared aboutContent module (the landing will reuse it). The random-game move limit
  inlines the 24h auto-match clock.
- App version: Vite define __APP_VERSION__ from VITE_APP_VERSION (default 'dev'), wired as
  a Docker build-arg sourced from `git describe --tags --always` in the deploy step — no
  manual version bumps. The fallback keeps a plain/local build working.

deploy/docker-compose.yml

@@ -79,6 +79,7 @@ services:
         VITE_TELEGRAM_BOT_ID: ${VITE_TELEGRAM_BOT_ID:-}
         VITE_TELEGRAM_LINK: ${VITE_TELEGRAM_LINK:-}
         VITE_GATEWAY_URL: ${VITE_GATEWAY_URL:-}
+        VITE_APP_VERSION: ${APP_VERSION:-dev}
     restart: unless-stopped
     depends_on: [backend]
     environment: