chore: фронт :3107, API :3001 (Docker, Vite, CORS, доки)

- compose: testing-web 3107:80, testing-backend 3001:3001, PORT+FRONTEND_URL
- nginx → testing-backend:3001; Vite 3107, proxy /api → 3001
- server default PORT 3001; Dockerfile EXPOSE 3001; CORS dev — localhost:3107
- README, журнал, user guide

Made-with: Cursor

backend/Dockerfile

@@ -3,6 +3,6 @@ WORKDIR /app
 COPY package.json package-lock.json* ./
 RUN npm ci
 COPY . .
-EXPOSE 3107
+EXPOSE 3001
 RUN chmod +x docker-entrypoint.sh
 ENTRYPOINT ["./docker-entrypoint.sh"]