fix(docker): remove apk add and dumb-init to avoid build timeout

Dockerfile

@@ -18,8 +18,8 @@ WORKDIR /app
 ENV NODE_ENV=production
 ENV PORT=3000
 
-# Install dumb-init for robust signal handling (PID 1)
+# Create uploads directory and set ownership for non-root node user
-RUN apk add --no-cache dumb-init && mkdir -p /app/uploads && chown -R node:node /app
+RUN mkdir -p /app/uploads && chown -R node:node /app
 
 # Switch to non-root user
 USER node
@@ -33,6 +33,4 @@ COPY --chown=node:node . .
 # Expose backend port
 EXPOSE 3000
 
-# Run container with dumb-init
-ENTRYPOINT ["/usr/bin/dumb-init", "--"]
 CMD ["node", "app.js"]