bug: fix player character data struct stats alignment

[hex-agon]

If we try to give the player N power slots with the current struct layout we'll observe that they do not work but instead are allocated to the curve stat.

Base stats:

Equipping a power item with power slot = 1, here we'd expect our power to be 28:

Yet if we equip a curve item, we can see it is raised to 14 instead of the expected 13:

The offsetted 4 bytes after the stats array is actually the character mastery level (0-10), if we set to 10 we can see the extra bonuses on the Character Mastery screen:

[jchv]

Thanks!