fix: use npm i instead of npm ci in Docker build, expose on port 5656

- Dockerfile: drop package-lock.json copy, use npm i instead of npm ci
  so install works even if lock file is slightly out of sync
- docker-compose: map host port 5656 → container port 3000

Dockerfile

@@ -3,8 +3,8 @@ FROM node:22-alpine AS build
 
 WORKDIR /app
 
-COPY package.json package-lock.json ./
-RUN npm ci
+COPY package.json ./
+RUN npm i
 
 COPY . .
 RUN npm run build
@@ -25,4 +25,4 @@ ENV PORT=3000
 ENV HOST=0.0.0.0
 EXPOSE 3000
 
-CMD ["node", "build"]
+CMD ["node", "build"]