fix: add curl to chat runtime image for healthcheck

backend/chat/Dockerfile

@@ -9,7 +9,7 @@ RUN go mod tidy
 RUN CGO_ENABLED=1 GOOS=linux go build -o /chat-server ./src/main.go
 
 FROM alpine:3.20
-RUN apk --no-cache add ca-certificates
+RUN apk --no-cache add ca-certificates curl curl
 WORKDIR /app
 COPY --from=builder /chat-server /usr/local/bin/chat-server