Scripts for replace-operator and asdb management

[pinebit]

Replace-Operator Workflow Automation

This PR adds automation scripts for the replace-operator workflow, enabling operators to safely replace a cluster member while preserving slashing protection.

Replace-Operator Scripts (scripts/edit/replace-operator/)

• remaining-operator.sh - Automates the complete workflow for operators staying in the cluster:
  • Export anti-slashing database
  • Run charon edit replace-operator ceremony
  • Update ASDB pubkeys for new cluster configuration
  • Backup and replace cluster-lock
  • Import updated ASDB
  • Restart containers
• new-operator.sh - Helps new operators join a cluster:
  • Generate ENR private key (--generate-enr)
  • Install new cluster-lock and start containers

Anti-Slashing Database Scripts (scripts/edit/vc/)

• export_asdb.sh / import_asdb.sh - Unified wrappers that auto-detect VC type from $VC env var
• update-anti-slashing-db.sh - Transforms pubkeys in exported ASDB when cluster-lock changes
• VC-specific implementations for Lodestar, Teku, Prysm, and Nimbus

Integration Tests

Replace-Operator Tests (scripts/edit/replace-operator/test/)

• 21 dry-run tests validating argument parsing, prerequisite checks, and workflow output
• Uses mocked Docker commands for isolation

ASDB Export/Import Tests (scripts/edit/vc/test/)

• Full integration tests for each VC type (Lodestar, Teku, Prysm, Nimbus)
• Tests actual export → transform → import cycle with test containers
• Isolated test data directories to avoid production interference