Tracking: Automated handling of unavailable counterparties

[julientinguely-da]

Description

The design of this feature and the requirements are described here.

Next implementation steps:

Milestone 1: Add persistent store (behind feature flag)

• Add dso_unavailable_parties DB schema and indices #6701
• Implement persistent store methods (addParties, removeParties) and backoff logic #6702
• Wire up persistent store to existing auto-ignore mechanism #6848

Milestone 2: New auto-ignore with backoff logic (behind feature flag)

• Automatic re-integration of ignored parties #7431
• Implement topology state lookups for supported Amulet versions
• Implement batch pre-sorting by lowest Amulet version #7224
• Implement recursive batch splitting execution loop #7225
• Implement targeted minimal-version exclusion and fallback logic
• Refactor ACS database queries to use anti-joins

Milestone 3: (behind feature flag)

• Implement background cleanup trigger
• Add safety list configuration
• Add Prometheus metrics for observability
• Document and release notes
• Enable triggers on clusters accordingly
• Retire unavailable parties feature flags #6817