Possible timestamp in Hall of Forms chambers

[Banpei-kun]

Version 4.7.0 changed the binary format of a Chamber in Hall of Forms by adding 8 bytes between the id_tag and id_num fields.

If we use an XOR cipher of 19 54 93 78 2E 15 8E 4E, we get something that looks like a timestamp:

• All chambers of events released up to and including June have a value of -1
• All chambers of events released since July have a value of 1546239600 = 2018-12-31T07:00:00Z

That would provide an explanation for why Book III (and newer) units no longer show up in Hall of Forms: the last Book II character with a timestamp is Ylgr (2018-12-21T07:00:00Z); the first Book III character with a timestamp is Tibarn (2019-02-11T07:00:00Z).