feat(rules): add alignment field to Combatant with axis gating flags

Adds the PF1e two-axis alignment code (LG/NG/CG/LN/N/CN/LE/NE/CE,
default N) to the Combatant model with a strict validator, derived
is_lawful/is_chaotic/is_good/is_evil properties, exposure in the
observation snapshot, and alignment values for all monsters and PCs
sourced from the bestiary KB and the Foundry sheets.

data/monsters/giant_belostomatid.json

@@ -1,5 +1,6 @@
 {
  "name": "Giant Belostomatid",
+ "alignment": "N",
  "level": 3,
  "size": "Large",
  "cr": "3",