chore: add pnpm workspace configuration for apps and packages

apps/backend/Dockerfile

@@ -0,0 +1,57 @@
+# apps/backend/Dockerfile
+FROM node:24-alpine AS base
+RUN npm install -g pnpm@8
+
+FROM base AS dependencies
+WORKDIR /app
+
+# Copy workspace configuration
+COPY pnpm-workspace.yaml package.json ./
+COPY apps/backend/package.json ./apps/backend/
+COPY packages/shared/package.json ./packages/shared/
+
+# Install dependencies
+RUN pnpm install --frozen-lockfile
+
+FROM base AS build
+WORKDIR /app
+COPY --from=dependencies /app/node_modules ./node_modules
+COPY --from=dependencies /app/apps/backend/node_modules ./apps/backend/node_modules
+COPY --from=dependencies /app/packages/shared/node_modules ./packages/shared/node_modules
+
+# Copy source code
+COPY packages/shared ./packages/shared
+COPY apps/backend ./apps/backend
+COPY prisma ./prisma
+
+# Build shared packages first
+RUN pnpm --filter @dreamchat/shared build
+
+# Generate Prisma client
+RUN pnpm db:generate
+
+# Build backend
+RUN pnpm --filter @dreamchat/backend build
+
+FROM base AS production
+WORKDIR /app
+
+# Copy only production dependencies
+COPY --from=dependencies /app/node_modules ./node_modules
+COPY --from=dependencies /app/apps/backend/node_modules ./apps/backend/node_modules
+COPY --from=build /app/apps/backend/dist ./dist
+COPY --from=build /app/packages/shared/dist ./node_modules/@dreamchat/shared/dist
+COPY --from=build /app/node_modules/.pnpm/@prisma+client* ./node_modules/.pnpm/
+COPY --from=build /app/node_modules/@prisma ./node_modules/@prisma
+
+# Create logs directory
+RUN mkdir -p /app/logs
+
+# Non-root user
+RUN addgroup -g 1001 -S nodejs
+RUN adduser -S nodejs -u 1001
+USER nodejs
+
+EXPOSE 3000
+
+CMD ["node", "dist/main.js"]