feat(combat): grant soft cover (+4 AC) to ranged attacks through creatures

tests/test_los.py

@@ -88,3 +88,31 @@ def test_cover_melee_uses_same_corner_rule_in_phase0() -> None:
 def test_cover_same_square_is_false() -> None:
     grid = make_grid(["."])
     assert has_cover(grid, (0, 0), (0, 0), ranged=True) is False
+
+
+def test_soft_cover_creature_between_grants_cover() -> None:
+    """A creature between shooter and target grants cover on ranged attacks."""
+    grid = make_grid([".....", ".....", "....."])
+    occupied = frozenset({(1, 2)})
+    assert has_cover(grid, (1, 0), (1, 4), ranged=True, occupied=occupied) is True
+
+
+def test_soft_cover_melee_ignores_creatures() -> None:
+    """Melee attacks ignore creatures for soft cover (CRB: ranged only)."""
+    grid = make_grid([".....", ".....", "....."])
+    occupied = frozenset({(1, 2)})
+    assert has_cover(grid, (1, 0), (1, 4), ranged=False, occupied=occupied) is False
+
+
+def test_soft_cover_creature_behind_target_ignored() -> None:
+    """A creature behind the target does not grant cover."""
+    grid = make_grid(["......", "......"])
+    occupied = frozenset({(1, 5)})
+    assert has_cover(grid, (1, 0), (1, 4), ranged=True, occupied=occupied) is False
+
+
+def test_soft_cover_creature_off_axis_ignored() -> None:
+    """A creature off the attack line does not grant cover."""
+    grid = make_grid([".....", "....."])
+    occupied = frozenset({(0, 2)})
+    assert has_cover(grid, (1, 0), (1, 4), ranged=True, occupied=occupied) is False