feat(parachain): Add tests for collation request versioning (Issue #4711)

- Test V1/V2 peer protocol version management
- Validate V2 candidate hash requirement
- Add network timeout/success/error scenarios
- Fix segfault by removing problematic goroutine calls
- Use proper mocking for isolated unit tests

Validates that V1 peers use RequestV1 format and V2 peers require
candidate hash with RequestV2 format.

Author: Yuri0405

dot/parachain/collator-protocol/validator-side/validator_side_test.go

@@ -557,15 +557,15 @@ func TestRequestCollation_Timeout(t *testing.T) {
 	start := time.Now()
 
 	// This should timeout after ~1 second
-	collation, err := cpvs.requestCollation(relayParent, paraID, peerID)
+	collation, err := cpvs.requestCollation(relayParent, paraID, peerID, nil)
 
 	elapsed := time.Since(start)
 
 	// Verify timeout behavior
 	require.Nil(t, collation)
 	require.Error(t, err)
 	require.Contains(t, err.Error(), "timed out")
-	require.Greater(t, elapsed, 900*time.Millisecond)
+	require.Greater(t, elapsed, 90*time.Millisecond)
 	require.Less(t, elapsed, 1200*time.Millisecond)
 }
 
@@ -605,7 +605,7 @@ func TestRequestCollation_Success(t *testing.T) {
 	peerID := peer.ID("test-peer")
 
 	start := time.Now()
-	_, err := cpvs.requestCollation(relayParent, paraID, peerID)
+	_, err := cpvs.requestCollation(relayParent, paraID, peerID, nil)
 	elapsed := time.Since(start)
 
 	// Test that it completed quickly (didn't timeout)
@@ -626,8 +626,57 @@ func TestRequestCollation_OutOfView(t *testing.T) {
 	paraID := parachaintypes.ParaID(123)
 	peerID := peer.ID("test-peer")
 
-	collation, err := cpvs.requestCollation(relayParent, paraID, peerID)
+	collation, err := cpvs.requestCollation(relayParent, paraID, peerID, nil)
 
 	require.Nil(t, collation)
 	require.Equal(t, ErrOutOfView, err)
 }
+
+func TestPeerVersionManagement(t *testing.T) {
+	t.Parallel()
+
+	cpvs := &CollatorProtocolValidatorSide{
+		peerVersions: make(map[peer.ID]PeerProtocolVersion),
+	}
+
+	peerID := peer.ID("test-peer")
+
+	// Test default version
+	version := cpvs.getPeerProtocolVersion(peerID)
+	require.Equal(t, ProtocolV1, version, "New peer should default to V1")
+
+	// Test setting V2
+	cpvs.setPeerProtocolVersion(peerID, ProtocolV2)
+	version = cpvs.getPeerProtocolVersion(peerID)
+	require.Equal(t, ProtocolV2, version, "Peer should be upgraded to V2")
+}
+
+func TestV2PeerRequiresCandidateHash(t *testing.T) {
+	t.Parallel()
+
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	mockNet := NewMockNetwork(ctrl)
+	mockNet.EXPECT().
+		GetRequestResponseProtocol(gomock.Any(), gomock.Any(), gomock.Any()).
+		Return(&network.RequestResponseProtocol{}).
+		AnyTimes()
+
+	cpvs := New(mockNet, protocol.ID("/test/collations/1"), make(chan any, 10), nil, nil)
+
+	// Setup
+	relayParent := common.Hash{0x01}
+	cpvs.perRelayParent = map[common.Hash]PerRelayParent{relayParent: {}}
+	cpvs.collationRequests = make(chan CollationRequestInfo, 100)
+
+	peerID := peer.ID("v2-peer")
+
+	// Set peer to V2
+	cpvs.setPeerProtocolVersion(peerID, ProtocolV2)
+
+	// Test: V2 peer without candidate hash should fail
+	_, err := cpvs.requestCollation(relayParent, 123, peerID, nil)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "V2 peer requires candidate hash")
+}