feat(rules): carried items + real steal transfers, unarmed-disarm auto-pickup

- Combatant.carried_items (APG Steal: non-wielded, non-closely-worn gear),
  loaded from JSON, seeded into CombatantState, exposed in the snapshot.
- _maneuver_steal: success transfers the first carried item victim -> thief
  (logged); empty list keeps the documented nothing-stealable behaviour.
- _maneuver_disarm: unarmed attacker's success auto-picks the dropped weapon
  into its carried_items (SRD Disarm); armed disarms unchanged. Dropped-weapon
  recovery via retrieve_weapon (move action) verified + pinned by tests.
- data/pcs: gear transcribed from Foundry sheet inventories (esha 13,
  jeanne 3, misty 9, nairda 7, oni 6, tammara 20); harvie/ierlieth/
  esha_mount and all monsters empty (no stealable inventory), noted in README.

tests/test_maneuvers.py

@@ -617,6 +617,75 @@ def test_steal_nothing_to_steal() -> None:
     assert "nothing stealable" in engine._transcript[-1]
 
 
+def test_steal_takes_one_carried_item() -> None:
+    # APG Steal: "If your attack is successful, you may take one item from
+    # your opponent" — one non-wielded, non-closely-worn carried item moves
+    # from the victim's list to the thief's (the engine takes the FIRST
+    # carried item; the RAW item choice has no action slot). The wielded
+    # sword stays with the victim.
+    a_spec = make_combatant("a", attack_bonus=2)
+    b_spec = make_combatant("b").model_copy(
+        update={"carried_items": ("potion of cure light wounds", "thieves' tools")}
+    )
+    a = make_state(a_spec, "players", (1, 1))
+    b = make_state(b_spec, "monsters", (1, 2))
+    engine = make_engine([1, 12], [a, b])
+    engine._execute_maneuver(a, b, "steal")
+    assert b.carried_items == ["thieves' tools"]
+    assert a.carried_items == ["potion of cure light wounds"]
+    assert "took potion of cure light wounds" in engine._transcript[-1]
+    assert engine.weapon_for(b, a) is not None  # the sword is untouched
+    # The observation snapshot exposes the transfer.
+    assert engine._combatant_snapshot(a)["carried_items"] == (
+        "potion of cure light wounds",
+    )
+    assert engine._combatant_snapshot(b)["carried_items"] == ("thieves' tools",)
+
+
+def test_disarmed_actor_recovers_weapon_with_a_move_action() -> None:
+    # SRD Disarm + "Picking up an item": the dropped sword lies in the
+    # victim's own square; retrieve_weapon (a move action) restores it and
+    # the weapon is usable again for a real attack.
+    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
+    b = make_state(make_combatant("b"), "monsters", (1, 2))
+    engine = make_engine([1, 12], [a, b])
+    engine._execute_maneuver(a, b, "disarm")
+    assert b.weapon_dropped == {"b-w"}
+    assert engine.weapon_for(b, a) is None
+    engine._retrieve_weapon(b, "b-w")
+    assert not b.weapon_dropped
+    assert engine.weapon_for(b, a) is not None
+    assert "retrieve b-w (restored)" in engine._transcript[-1]
+
+
+def test_unarmed_disarm_success_auto_picks_up_the_weapon() -> None:
+    # SRD Disarm: "If you successfully disarm your opponent without using a
+    # weapon, you may automatically pick up the item dropped." a is unarmed
+    # (no melee weapon at all): the dropped sword lands in a's carried_items
+    # (held, not wielded) with no retrieve move action spent.
+    a_spec = make_combatant("a", attack_bonus=2).model_copy(update={"attacks": []})
+    b_spec = make_combatant("b")
+    a = make_state(a_spec, "players", (1, 1))
+    b = make_state(b_spec, "monsters", (1, 2))
+    engine = make_engine([1, 12], [a, b])
+    engine._execute_maneuver(a, b, "disarm")
+    assert b.weapon_dropped == {"b-w"}
+    assert a.carried_items == ["sword"]
+    assert "unarmed disarm pickup (sword taken)" in engine._transcript[-1]
+
+
+def test_armed_disarm_success_does_not_pick_up() -> None:
+    # The automatic pickup is reserved to unarmed disarms: an armed success
+    # leaves the weapon on the ground (victim's weapon_dropped only).
+    a = make_state(make_combatant("a", attack_bonus=2), "players", (1, 1))
+    b = make_state(make_combatant("b"), "monsters", (1, 2))
+    engine = make_engine([1, 12], [a, b])
+    engine._execute_maneuver(a, b, "disarm")
+    assert b.weapon_dropped == {"b-w"}
+    assert a.carried_items == []
+    assert engine._transcript[-1].endswith("SUCCESS (sword dropped)")
+
+
 def test_reposition_distance_scales_with_margin() -> None:
     # APG Reposition: "For every 5 by which your attack exceeds your
     # opponent's CMD, you can move the target an additional 5 feet."