feat: add Docker support with PostgreSQL and health check endpoint

Dockerfile

@@ -0,0 +1,58 @@
+# Multi-stage build for EuchreCamp Next.js application
+
+# Stage 1: Builder
+FROM node:20-alpine AS builder
+
+# Install dependencies
+RUN apk add --no-cache python3 make g++
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies (including dev dependencies for building)
+RUN npm ci
+
+# Copy source code
+COPY . .
+
+# Build the application
+RUN npm run build
+
+# Stage 2: Runner
+FROM node:20-alpine AS runner
+
+# Install dumb-init for proper signal handling
+RUN apk add --no-cache dumb-init
+
+# Create non-root user
+RUN addgroup --system --gid 1001 euchre && \
+    adduser --system --uid 1001 --ingroup euchre euchre
+
+# Set working directory
+WORKDIR /app
+
+# Copy built application from builder
+COPY --from=builder --chown=euchre:euchre /app/.next ./.next
+COPY --from=builder --chown=euchre:euchre /app/public ./public
+COPY --from=builder --chown=euchre:euchre /app/package.json ./package.json
+COPY --from=builder --chown=euchre:euchre /app/prisma ./prisma
+
+# Install only production dependencies
+RUN npm ci --omit=dev
+
+# Switch to non-root user
+USER euchre
+
+# Expose port
+EXPOSE 3000
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:3000/api/health || exit 1
+
+# Start command
+ENTRYPOINT ["dumb-init", "--"]
+CMD ["npm", "start"]