feat: Phase 5 design doc and pre-testing hardening

[loki-hermes-agent]

Summary

Prepares the project for functional testing on the eth-docker deployment and lays the groundwork for Phase 5.

Changes:

1. Phase 5 Design: Created docs/runbook-synthesis.md detailing the synthesis algorithm, minimum data requirements (10+ resolved incidents), output format (runbooks/drafts/), and the mandatory human review gate.
2. Missing Runbooks: Added runbooks/validator_duty_misses.yaml and runbooks/client_crash.yaml to provide meaningful test coverage for common failure modes.
3. Heartbeat Metric: Added prometheus-client dependency and implemented hermes_alive Gauge in processor.py, exposed via an HTTP server on port 8091. This enables the HermesAgentSilent alert.
4. Prometheus Alerts: Created docs/prometheus-alerts.yml containing HermesAgentSilent and WebhookReceiverDown alert rules as specified in the design docs.
5. Docker & Entry Point: Created the root Dockerfile for hermes-agent (using uv) and added an if __name__ == "__main__": block to processor.py so it can be run directly as python -m agentic_node_ops.processor.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Testing

• All existing tests pass (pytest -v --cov=agentic_node_ops --cov=webhook_receiver — 161 tests passed, 89% coverage)
• Linting and formatting (ruff check & ruff format) applied and passing

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation

[itenev]

this pr will be split into atomic prs