fix(combat): resolve touch attacks against touch AC and firearms

src/pf1e_simulator/models.py

@@ -237,7 +237,9 @@ class AttackSpec(_FrozenModel):
 
     `count` captures repeated identical swings ("2x Talons") without listing
     the same entry twice. `reach_ft` applies to melee/touch kinds,
-    `range_increment_ft` to ranged/touch kinds.
+    `range_increment_ft` to ranged/touch kinds. `firearm` marks a ranged-touch
+    weapon (gun) whose shots resolve against touch AC within the first range
+    increment and against full AC beyond it.
     """
 
     id: str
@@ -251,6 +253,7 @@ class AttackSpec(_FrozenModel):
     reach_ft: int = 5
     range_increment_ft: int | None = None
     count: int = Field(default=1, ge=1)
+    firearm: bool = False
 
 
 class DamageReduction(_FrozenModel):