feat: persist fenced client command events

internal/server/store/event.go

@@ -33,6 +33,7 @@ func (function FaultInjectorFunc) Checkpoint(name string) error { return functio
 
 type EventAppend struct {
 	IssueUUID        [16]byte
+	ClientID         string
 	EventSeq         uint64
 	ObservedUnixNano int64
 	ReceiptUnixNano  int64
@@ -80,11 +81,17 @@ func (store *Store) AppendCommandEvent(ctx context.Context, event EventAppend) (
 	}
 	var lastSequence, commandOutputCharged, commandCharged, clientCharged, serverCharged, closeoutRemaining uint64
 	var clientID string
-	err = database.QueryRowContext(ctx, `SELECT commands.last_event_seq, commands.output_charged_bytes,
+	query := `SELECT commands.last_event_seq, commands.output_charged_bytes,
 commands.charged_bytes, commands.closeout_remaining_bytes, commands.client_id, clients.charged_bytes,
 storage_counters.command_charged_bytes
 FROM commands JOIN clients ON clients.client_id = commands.client_id
-JOIN storage_counters ON storage_counters.singleton = 1 WHERE commands.issue_uuid = ?`, event.IssueUUID[:]).Scan(
+JOIN storage_counters ON storage_counters.singleton = 1 WHERE commands.issue_uuid = ?`
+	arguments := []any{event.IssueUUID[:]}
+	if event.ClientID != "" {
+		query += ` AND commands.client_id = ?`
+		arguments = append(arguments, event.ClientID)
+	}
+	err = database.QueryRowContext(ctx, query, arguments...).Scan(
 		&lastSequence, &commandOutputCharged, &commandCharged, &closeoutRemaining, &clientID, &clientCharged, &serverCharged)
 	if errors.Is(err, sql.ErrNoRows) {
 		return result, ErrCommandNotFound