feat(observation): expose per-pair cover bonus

src/pf1e_simulator/combat.py

@@ -1025,6 +1025,21 @@ class CombatEngine:
         for cell in occupied:
             for enemy in self.enemies_threatening(state, cell):
                 threatening_enemies.add(enemy.combatant.id)
+        cover_bonus = 0
+        if weapon is not None:
+            others = frozenset(
+                cell
+                for s in self._states
+                if s.active and s is not state and s is not target
+                for cell in s.occupied_cells()
+            )
+            cover_bonus = cover_bonus_cells(
+                self._grid,
+                state.occupied_cells(),
+                target.occupied_cells(),
+                ranged=self._is_ranged_attack(weapon),
+                occupied=others,
+            )
         return {
             "target_index": self._states.index(target),
             "distance_ft": distance_ft,
@@ -1039,6 +1054,7 @@ class CombatEngine:
             "movement_cost_ft": self.movement_cost_ft(state, target),
             "target_threatens_me": target_threatens_me,
             "enemies_threatening_me": len(threatening_enemies),
+            "cover_bonus": cover_bonus,
         }
 
     def _take_turn(self, state: CombatantState) -> bool: