fix: Docker multi-stage build for sqlite3, health endpoint, productValidator exports

- Dockerfile: multi-stage build (builder with python3+g++ for native addons)
- Dockerfile: wireguard-tools from edge/community repo
- Dockerfile: removed USER appuser (start.sh needs root for wg-quick)
- Dockerfile: health check on port 3000
- Added /health HTTP endpoint in index.js for Docker healthcheck
- Fixed productValidator.js: added named exports (validateProductName, validateProductPrice)
- Added better-sqlite3 as fallback dependency

Dockerfile

@@ -1,36 +1,47 @@
+FROM node:22-alpine AS builder
+
+WORKDIR /app
+
+# Install build dependencies for native modules (sqlite3, better-sqlite3)
+RUN apk add --no-cache python3 make g++
+
+COPY package*.json ./
+RUN npm install && npm cache clean --force
+
+# --- Runtime image ---
 FROM node:22-alpine
 
-# Устанавливаем необходимые пакеты
-RUN apk update && \
-    apk add --no-cache \
+# Install runtime dependencies
+# WireGuard needs community repo on some alpine versions
+RUN apk add --no-cache --repository https://dl-cdn.alpinelinux.org/alpine/edge/community \
     wireguard-tools \
+    && apk add --no-cache \
     iptables \
     iproute2 \
     openresolv \
     bash \
-    curl && \
-    rm -rf /var/cache/apk/*
+    curl \
+    && rm -rf /var/cache/apk/*
 
-# Создаём непривилегированного пользователя
-RUN addgroup -S appgroup && \
-    adduser -S appuser -G appgroup
-
-# Рабочая директория
 WORKDIR /app
 
-# Копируем зависимости и устанавливаем их
+# Copy node_modules from builder (with native addons pre-compiled)
+COPY --from=builder /app/node_modules ./node_modules
 COPY package*.json ./
-RUN npm install
 
-# Копируем исходный код с правильным владельцем
-COPY --chown=appuser:appgroup ./src ./src
+# Copy application source
+COPY ./src ./src
 
-# Копируем скрипт запуска
-COPY --chown=appuser:appgroup ./wg/start.sh /app/start.sh
+# Copy startup script
+COPY ./wg/start.sh /app/start.sh
 RUN chmod +x /app/start.sh
 
-# Переключаемся на непривилегированного пользователя
-USER appuser
+# Create db directory
+RUN mkdir -p /app/db
 
-# Команда для запуска
-CMD ["/bin/bash", "/app/start.sh"]
+# Health check: bot responds to /health on port 3000
+HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
+    CMD curl -sf http://localhost:3000/health || exit 1
+
+# start.sh runs as root (needed for wg-quick), then drops to node
+CMD ["/bin/bash", "/app/start.sh"]