fix: add missing session.Init() call in CGGMP21 signing handler

The CGGMP21 signing handler never called session.Init(), which creates
the protocol handler. Without it, no protocol round messages are
generated and the signing session stalls indefinitely.

pkg/eventconsumer/signing_handler_cggmp21.go

@@ -78,6 +78,9 @@ func (ec *eventConsumer) handleSigningEventCGGMP21(msg *types.SignTxMessage, nat
 	// Mark session as already processed
 	ec.addSession(msg.WalletID, msg.TxID)
 
+	// Initialize the signing session (creates protocol handler)
+	session.Init()
+
 	ctx, done := context.WithCancel(context.Background())
 
 	// Monitor for errors