refactor(p2p): remove InMemoryAttestationPool, use KvAttestationPool everywhere

- Delete memory_attestation_pool.ts and memory_attestation_pool.test.ts
- Add createTestAttestationPool() factory function for test setup
- Update p2p_client.test.ts to use createTestAttestationPool()
- Update index.ts exports to export KvAttestationPool instead of InMemoryAttestationPool

The InMemoryAttestationPool in test-helpers/testbench-utils.ts is kept as a
minimal mock for benchmarking purposes.

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: spalladino

yarn-project/p2p/src/client/p2p_client.test.ts

@@ -24,8 +24,9 @@ import { expect, jest } from '@jest/globals';
 import { type MockProxy, mock } from 'jest-mock-extended';
 
 import type { P2PConfig } from '../config.js';
-import { InMemoryAttestationPool, type P2PService } from '../index.js';
+import type { P2PService } from '../index.js';
 import type { AttestationPool } from '../mem_pools/attestation_pool/attestation_pool.js';
+import { createTestAttestationPool } from '../mem_pools/attestation_pool/kv_attestation_pool.js';
 import type { MemPools } from '../mem_pools/interface.js';
 import { AztecKVTxPool } from '../mem_pools/tx_pool/aztec_kv_tx_pool.js';
 import type { TxPool } from '../mem_pools/tx_pool/index.js';
@@ -60,7 +61,7 @@ describe('P2P Client', () => {
     txCollection = mock<TxCollection>();
     txCollection.getConstants.mockReturnValue(l1Constants);
 
-    attestationPool = new InMemoryAttestationPool();
+    attestationPool = await createTestAttestationPool();
 
     blockSource = new MockL2BlockSource();
     await blockSource.createBlocks(100);

yarn-project/p2p/src/mem_pools/attestation_pool/index.ts

@@ -1,2 +1,2 @@
 export * from './attestation_pool.js';
-export * from './memory_attestation_pool.js';
+export * from './kv_attestation_pool.js';

yarn-project/p2p/src/mem_pools/attestation_pool/kv_attestation_pool.ts

@@ -374,3 +374,10 @@ export class KvAttestationPool implements AttestationPool {
     return count;
   }
 }
+
+/** Creates a KvAttestationPool backed by a temporary store for testing. */
+export async function createTestAttestationPool(telemetry?: TelemetryClient): Promise<KvAttestationPool> {
+  const { openTmpStore } = await import('@aztec/kv-store/lmdb-v2');
+  const store = await openTmpStore('test-attestation-pool');
+  return new KvAttestationPool(store, telemetry);
+}