MEM-003 | Add EEPROM coherence record format

[wxkim]

Problem statement: what's wrong with it?

• Stored records can be corrupted without clear validation.

Ideal situation: describe the solution you'd like.

• Add record metadata with version, length, CRC/checksum.

Proposed solutions: describe alternatives you've considered

• No integrity check vs lightweight CRC format (preferred).

Additional context

• Covers coherence/integrity requirement.