[PHASE-7] Remove validation from message decoder

internal/protocol/message_decoder.go

@@ -25,11 +25,6 @@ func (d *MessageDecoder) Decode(r io.Reader) (*Message, error) {
 		return nil, fmt.Errorf("failed to read message type: %w", err)
 	}
 
-	// Validate message type (only request types are valid for server)
-	if !isValidRequestType(msgType) {
-		return nil, fmt.Errorf("invalid message type: 0x%02x", msgType)
-	}
-
 	// Read payload length (4 bytes, big-endian)
 	var payloadLength uint32
 	if err := binary.Read(r, binary.BigEndian, &payloadLength); err != nil {
@@ -53,13 +48,3 @@ func (d *MessageDecoder) Decode(r io.Reader) (*Message, error) {
 		PayloadStream:  payloadStream,
 	}, nil
 }
-
-// isValidRequestType checks if the message type is a valid request type
-func isValidRequestType(msgType MessageType) bool {
-	switch msgType {
-	case ChallengeRequestType, SolutionRequestType:
-		return true
-	default:
-		return false
-	}
-}

internal/protocol/message_decoder_test.go

@@ -70,16 +70,6 @@ func TestMessageDecoder_Decode_Errors(t *testing.T) {
 			data:    []byte{},
 			wantErr: "EOF",
 		},
-		{
-			name:    "invalid message type",
-			data:    []byte{0xFF, 0x00, 0x00, 0x00, 0x00},
-			wantErr: "invalid message type",
-		},
-		{
-			name:    "response type not allowed",
-			data:    []byte{0x02, 0x00, 0x00, 0x00, 0x00}, // ChallengeResponseType
-			wantErr: "invalid message type",
-		},
 		{
 			name:    "incomplete header",
 			data:    []byte{0x01, 0x00, 0x00},