Add Dockerfile and fix pnpm setup for Dokploy

Dockerfile

@@ -1,15 +1,15 @@
+# To use this Dockerfile, you have to set `output: 'standalone'` in your next.config.js file.
+
+FROM node:20-alpine AS base
+
 # Install dependencies only when needed
 FROM base AS deps
 RUN apk add --no-cache libc6-compat
 WORKDIR /app
 
-COPY package.json yarn.lock* package-lock.json* pnpm-lock.yaml* ./
-RUN \
-  if [ -f yarn.lock ]; then yarn --frozen-lockfile; \
-  elif [ -f package-lock.json ]; then npm ci; \
-  elif [ -f pnpm-lock.yaml ]; then corepack enable && corepack prepare pnpm@10.11.0 --activate && pnpm i --frozen-lockfile; \
-  else echo "Lockfile not found." && exit 1; \
-  fi
+# Copy lockfile and install deps with pnpm
+COPY package.json pnpm-lock.yaml ./
+RUN corepack enable && corepack prepare pnpm@10.11.0 --activate && pnpm i --frozen-lockfile
 
 # Rebuild the source code only when needed
 FROM base AS builder
@@ -17,9 +17,30 @@ WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
 
-RUN \
-  if [ -f yarn.lock ]; then yarn run build; \
-  elif [ -f package-lock.json ]; then npm run build; \
-  elif [ -f pnpm-lock.yaml ]; then corepack enable && corepack prepare pnpm@10.11.0 --activate && pnpm run build; \
-  else echo "Lockfile not found." && exit 1; \
-  fi
+# Enable corepack again for build stage
+RUN corepack enable && corepack prepare pnpm@10.11.0 --activate && pnpm run build
+
+# Production image, copy all the files and run next
+FROM base AS runner
+WORKDIR /app
+
+ENV NODE_ENV=production
+
+RUN addgroup --system --gid 1001 nodejs
+RUN adduser --system --uid 1001 nextjs
+
+COPY --from=builder /app/public ./public
+
+RUN mkdir .next
+RUN chown nextjs:nodejs .next
+
+COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
+
+USER nextjs
+
+EXPOSE 3000
+ENV PORT=3000
+ENV HOSTNAME="0.0.0.0"
+
+CMD ["node", "server.js"]