statement-store: close correctness test coverage gaps

[AndreiEres]

Summary

Tracking issue for the remaining correctness scenarios in statement-store tests. See details in the testing strategy.

Tasks

P0

• Propagation under normal load: unit tests and Zombienet tests to cover concurrent multi-client corner cases and verify statements reach all real nodes, including during major sync
  • Unit tests statement-store: add concurrent and multi-peer propagation tests #11611
  • Zombienet tests for propagation Add statement store e2e integration tests #11237
  • Propagation during major sync Statement-store: defer statement protocol connections during major sync #11487
• Eviction: unit tests verify the lowest-priority statements are evicted first, corner cases of priority ordering. statement-store: add eviction priority ordering tests #11615
• Channel replacement: unit tests verify only higher-priority statements replace existing entries, corner cases of replacement logic. statement-store: add channel replacement logic tests #11617
• Malformed input: unit tests verify invalid and corrupt payloads are rejected, can be extended with fuzzing statement-store: Add malformed input unit tests #11673

P1

• Initial sync: Zombienet tests verify a new node joins a live network and receives the full statement set statement-store: zombienet initial sync #11861
• Subscription reconnection: unit tests and Zombienet tests verify reconnecting subscribers receive current state
  • Unit tests statement-store: add subscription reconnection tests #11618
  • Zombienet statement-store: zombienet integration test for subscription reconnection #11864
• Mass expiration: Zombienet tests verify responsiveness and consistency under concurrent submissions statement-store: add mass expiration zombienet integration test #11663

P2

• Data integrity: unit tests verify byte-identical content after encode/decode roundtrip