Implement map serialization and deserialization

Approach: Length-Prefixed Encoding with Sorted Keys A delimiter-based format such as key:value; is fragile because the strings themselves can contain :, ;, , =, spaces, or even #. The core problem is that the parser cannot tell which occurrences of a separator are structural and which are content. The fix is to stop relying on reserved characters inside the payload. Before writing each key or value, write its length as a decimal integer followed by #. The parser reads the…