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.

src/pf1e_simulator/loaders/combatant.py

@@ -237,6 +237,8 @@ def load_combatant(path: Path) -> Combatant:
     ``_resolve_feat``.  ``spells`` are passed through as-is (list of strings).
     The ``aware`` flag (SRD "Surprise") is a plain boolean of the
     ``Combatant`` schema (default ``true``), so it parses directly here.
+    The ``alignment`` code (SRD "Alignment") is a plain string of the schema
+    (default ``"N"``), so a JSON ``alignment`` key loads directly too.
     """
     try:
         raw = path.read_text(encoding="utf-8")