cardano-scaling/hydra

AI Summary: Implement an HTTP API endpoint for submitting transactions to the Hydra node, mirroring the functionality of existing WebSocket API. The API should return a transaction hash upon successful submission, optionally with confirmation of inclusion in a snapshot. Consider offering both immediate and confirmation-based response options.

AI Summary: Implement new metrics for the Hydra Head protocol, specifically tracking the number of expected peers, the etcd quorum threshold, and the number of failed transactions. These metrics will be exposed via a Prometheus-compatible endpoint for health checking purposes.

AI Summary: Decouple the metrics reporting functionality from the logging system in the Hydra Head protocol implementation. The goal is to ensure that metrics are still collected and reported even when logging is disabled, providing a complete view of the node's operational status regardless of the logging configuration.