feat: enhance string decoding error handling in RealDecoder

Added checks to ensure the remaining bytes are sufficient for string lengths in GetString, GetNullableString, GetCompactString, and GetCompactNullableString methods. Improved error messages to provide clearer feedback on expected versus actual byte lengths during decoding.

protocol/decoder/real_decoder.go

@@ -256,6 +256,11 @@ func (rd *RealDecoder) GetString() (string, error) {
 		return "", err
 	}
 
+	if rd.Remaining() < n {
+		rem := rd.Remaining()
+		return "", errors.NewPacketDecodingError(fmt.Sprintf("Expected string length to be %d bytes, got %d bytes", n, rem), "STRING")
+	}
+
 	tmpStr := string(rd.raw[rd.off : rd.off+n])
 	rd.off += n
 	return tmpStr, nil
@@ -270,6 +275,11 @@ func (rd *RealDecoder) GetNullableString() (*string, error) {
 		return nil, err
 	}
 
+	if rd.Remaining() < n {
+		rem := rd.Remaining()
+		return nil, errors.NewPacketDecodingError(fmt.Sprintf("Expected string length to be %d bytes, got %d bytes", n, rem), "NULLABLE_STRING")
+	}
+
 	tmpStr := string(rd.raw[rd.off : rd.off+n])
 	rd.off += n
 	return &tmpStr, nil
@@ -288,6 +298,12 @@ func (rd *RealDecoder) GetCompactString() (string, error) {
 	if length < 0 {
 		return "", errors.NewPacketDecodingError(fmt.Sprintf("Expected COMPACT_STRING length to be > 0, got %d", length), "COMPACT_STRING")
 	}
+
+	if rd.Remaining() < length {
+		rem := rd.Remaining()
+		return "", errors.NewPacketDecodingError(fmt.Sprintf("Expected string length to be %d bytes, got %d bytes", length, rem), "COMPACT_STRING")
+	}
+
 	tmpStr := string(rd.raw[rd.off : rd.off+length])
 	rd.off += length
 	return tmpStr, nil
@@ -308,6 +324,11 @@ func (rd *RealDecoder) GetCompactNullableString() (*string, error) {
 		return nil, errors.NewPacketDecodingError(fmt.Sprintf("Expected compact nullable string length to be > 0, got %d", length), "COMPACT_NULLABLE_STRING")
 	}
 
+	if rd.Remaining() < length {
+		rem := rd.Remaining()
+		return nil, errors.NewPacketDecodingError(fmt.Sprintf("Expected string length to be %d bytes, got %d bytes", length, rem), "COMPACT_NULLABLE_STRING")
+	}
+
 	tmpStr := string(rd.raw[rd.off : rd.off+length])
 	rd.off += length
 	return &tmpStr, nil
@@ -456,9 +477,7 @@ func (rd *RealDecoder) GetRawBytesFromOffset(length int) ([]byte, error) {
 
 	if rd.off >= len(rd.raw) {
 		return nil, errors.NewPacketDecodingError(fmt.Sprintf("Expected offset to be less than length of raw bytes (%d), got %d", len(rd.raw), rd.off), "RAW_BYTES_FROM_OFFSET")
-	}
-
-	if rd.off+length > len(rd.raw) {
+	} else if rd.off+length > len(rd.raw) {
 		return nil, errors.NewPacketDecodingError(fmt.Sprintf("Expected offset to be less than length of raw bytes (%d), got %d", len(rd.raw), rd.off), "RAW_BYTES_FROM_OFFSET")
 	}