feat(combat): apply cumulative -2 range penalties per increment

tests/test_combat.py

@@ -569,3 +569,98 @@ def test_ranged_no_line_of_effect_unreachable_target_waits() -> None:
     engine = CombatEngine(ScriptedRng([10, 9]), grid, states, round_cap=1)
     result = engine.run()
     assert result.transcript[2] == "round 1 archer: wait"
+
+
+def test_ranged_penalty_zero_within_first_increment() -> None:
+    """Within the first range increment (5 ft of 10), no penalty applies."""
+    archer = make_combatant("archer", attack_bonus=4, kind="ranged", range_increment_ft=10)
+    target = make_combatant("target", ac=13)
+    states = [make_state(archer, "players", (1, 1)), make_state(target, "monsters", (1, 2))]
+    engine = CombatEngine(ScriptedRng([12, 3]), make_grid(), states)
+    result = engine.resolve_attack(states[0], states[1], archer.attacks[0])
+    assert result.penalty == 0
+    assert result.total == 16  # 12 + 4
+    assert result.hit is True
+
+
+def test_ranged_penalty_beyond_first_increment() -> None:
+    """At 15 ft (2nd full increment of 10 ft), the attack suffers -2."""
+    archer = make_combatant("archer", attack_bonus=4, kind="ranged", range_increment_ft=10)
+    target = make_combatant("target", ac=13)
+    states = [make_state(archer, "players", (1, 1)), make_state(target, "monsters", (1, 4))]
+    engine = CombatEngine(ScriptedRng([12, 3]), make_grid(), states)
+    result = engine.resolve_attack(states[0], states[1], archer.attacks[0])
+    assert result.penalty == -2
+    assert result.total == 14  # 12 + 4 - 2
+    assert result.hit is True
+
+
+def test_ranged_penalty_scales_with_more_increments() -> None:
+    """At 25 ft (3rd full increment of 10 ft), the penalty reaches -4."""
+    archer = make_combatant("archer", attack_bonus=4, kind="ranged", range_increment_ft=10)
+    target = make_combatant("target", ac=13)
+    states = [make_state(archer, "players", (1, 1)), make_state(target, "monsters", (1, 6))]
+    engine = CombatEngine(ScriptedRng([12, 3]), make_grid(), states)
+    result = engine.resolve_attack(states[0], states[1], archer.attacks[0])
+    assert result.penalty == -4
+    assert result.total == 12  # 12 + 4 - 4: now a MISS vs AC 13
+    assert result.hit is False
+
+
+def test_ranged_penalty_shown_in_transcript() -> None:
+    """The log line renders the penalty between bonus and total."""
+    archer = make_combatant("archer", attack_bonus=4, kind="ranged", range_increment_ft=10)
+    target = make_combatant("target", speed=0)
+    states = [make_state(archer, "players", (1, 1)), make_state(target, "monsters", (1, 4))]
+    engine = CombatEngine(ScriptedRng([10, 9, 12, 3]), make_grid(), states, round_cap=1)
+    result = engine.run()
+    assert result.transcript == (
+        "initiative: archer d20=10+0=10",
+        "initiative: target d20=9+0=9",
+        "round 1 archer: short bow vs target d20=12+4-2=14 AC 13 -> HIT 3 damage (6->3)",
+        "round 1 target: wait",
+        "battle over: draw after 1 rounds",
+    )
+
+
+def test_ranged_penalty_applies_to_crit_confirm() -> None:
+    """The -2 range penalty also applies to the crit confirmation roll."""
+    archer = make_combatant("archer", attack_bonus=4, kind="ranged", range_increment_ft=10)
+    target = make_combatant("target", ac=15)
+    states = [make_state(archer, "players", (1, 1)), make_state(target, "monsters", (1, 4))]
+    # Natural 20 threatens; confirm 12 would beat AC 15 without the penalty
+    # (12 + 4 = 16) but fails with it (12 + 4 - 2 = 14).
+    engine = CombatEngine(ScriptedRng([20, 12, 3]), make_grid(), states)
+    result = engine.resolve_attack(states[0], states[1], archer.attacks[0])
+    assert result.hit is True
+    assert result.crit is False
+    assert result.damage == 3  # not doubled
+
+
+def test_ranged_weapon_usable_at_maximum_range() -> None:
+    """At exactly 10 range increments the weapon is still usable, with -18."""
+    legend = {".": TerrainType(type="floor", move_cost=1)}
+    spec = MapSpec(name="range-max", terrain=("." * 24,), legend=legend)
+    grid = Grid.from_spec(spec)
+    archer = make_combatant("archer", attack_bonus=4, kind="ranged", range_increment_ft=10)
+    target = make_combatant("target", ac=13)
+    states = [make_state(archer, "players", (0, 0)), make_state(target, "monsters", (0, 20))]
+    engine = CombatEngine(ScriptedRng([20, 3, 3]), grid, states)
+    assert engine.weapon_for(states[0], states[1]) is not None
+    result = engine.resolve_attack(states[0], states[1], archer.attacks[0])
+    assert result.penalty == -18
+    assert result.hit is True  # natural 20
+
+
+def test_ranged_weapon_unusable_beyond_maximum_range() -> None:
+    """Beyond 10 range increments the weapon is dropped and the policy moves."""
+    legend = {".": TerrainType(type="floor", move_cost=1)}
+    spec = MapSpec(name="range-beyond", terrain=("." * 24,), legend=legend)
+    grid = Grid.from_spec(spec)
+    archer = make_combatant("archer", attack_bonus=4, kind="ranged", range_increment_ft=10)
+    target = make_combatant("target", speed=0)
+    states = [make_state(archer, "players", (0, 0)), make_state(target, "monsters", (0, 21))]
+    engine = CombatEngine(ScriptedRng([10, 9]), grid, states, round_cap=1)
+    assert engine.weapon_for(states[0], states[1]) is None
+    result = engine.run()
+    assert result.transcript[2] == "round 1 archer: move (0,0)->(0,1)"