trac-msb v0.2.7

Changes

- Refactored validator selection: message thresholds, retries/timeouts, connection cleanup, and a new MessageOrchestrator for more stable communication.
- Fixed connection pool overflow and slow validator pool filling.
- Fixed transaction broadcast handling.

Other

- Temporarily disabled dependency install and unit tests in the publish workflow (unstable on GH runners).
- package.json bumped to 0.2.7.