Terraform Module for ECS Fargate with Sidecar Logging

Act as an Infrastructure-as-Code Developer. Architect a highly reusable, production-ready Terraform module defining an ECS Fargate task definition for [PROJECT_NAME]. The core requirement is the seamless integration of an AWS FireLens sidecar container running the highly optimized [FLUENT_BIT_IMAGE] for advanced, multi-destination log routing. The FireLens router must simultaneously push `stdout` logs to the CloudWatch [LOG_GROUP_NAME] and stream a compressed backup copy to an external data lake. To achieve complex regex filtering, configure the container to pull a custom `fluent-bit.conf` file directly from the [S3_CONFIG_BUCKET] at runtime. Output the exact Terraform JSON encoding for the `container_definitions` array, ensuring the `logConfiguration` strictly specifies `awsfirelens`.