로스트 시티 클래식 코어 이식

맥락:
- 새 레포의 첫 범위를 RL 없는 Lost Cities classic 게임 구현으로 잡았다.
- 기존 tier0-3 실험 축은 제거하고 classic 5-expedition 룰을 기본값으로 둔다.

변경:
- games/classic 아래에 Cython 게임 엔진, env, bots, backend 경계, Rust core와 proto schema를 이식했다.
- setuptools/Cython 빌드 설정과 package data, README, classic port notes를 추가했다.
- 룰, 점수, 마스크, env, canonical state, bot, Rust parity 테스트를 새 경로로 가져왔다.

확인:
- uv run pytest tests/games/classic
- uv run lost-cities-classic

tests/games/classic/test_canonical_state.py

@@ -0,0 +1,136 @@
+import json
+import random
+from pathlib import Path
+
+import pytest
+
+import coolrl_lost_cities.games.classic as classic
+from coolrl_lost_cities.games.classic.game import Card, GameState, LostCitiesConfig
+
+
+FIXTURE_DIR = Path(classic.__file__).resolve().parent / "fixtures"
+
+
+def _small_config() -> LostCitiesConfig:
+    return LostCitiesConfig(
+        n_colors=2,
+        n_ranks=2,
+        min_rank=1,
+        n_handshakes=0,
+        hand_size=1,
+        expedition_penalty=0,
+        bonus_threshold=99,
+        bonus_amount=0,
+    )
+
+
+def test_new_game_from_deck_uses_explicit_internal_deck_order() -> None:
+    config = _small_config()
+    state = GameState.new_game_from_deck(
+        [
+            Card(0, 1),
+            Card(0, 2),
+            Card(1, 1),
+            Card(1, 2),
+        ],
+        config,
+    )
+
+    assert state.hands == [[Card(1, 2)], [Card(1, 1)]]
+    assert state.deck == [Card(0, 1), Card(0, 2)]
+    state.validate_invariants()
+
+
+def test_snapshot_roundtrip_preserves_json_state() -> None:
+    state = GameState.new_game(LostCitiesConfig(seed=5))
+    first_action = next(
+        index for index, legal in enumerate(state.unified_legal_mask()) if legal
+    )
+    state.apply_unified_action(first_action)
+    second_action = next(
+        index for index, legal in enumerate(state.unified_legal_mask()) if legal
+    )
+    state.apply_unified_action(second_action)
+
+    payload = json.loads(json.dumps(state.to_snapshot()))
+    restored = GameState.from_snapshot(payload)
+
+    assert restored.to_snapshot() == state.to_snapshot()
+    restored.validate_invariants()
+
+
+def test_validate_invariants_detects_card_loss() -> None:
+    state = GameState.new_game(LostCitiesConfig(seed=7))
+    state.deck.pop()
+
+    with pytest.raises(ValueError, match="card conservation"):
+        state.validate_invariants()
+
+
+def test_validate_invariants_detects_bad_expedition_order() -> None:
+    state = GameState.new_game(LostCitiesConfig(seed=8))
+    card = state.deck.pop()
+    state.expeditions[0][card.color].extend([Card(card.color, 2), Card(card.color, 1)])
+    state.deck.extend([Card(card.color, 2), Card(card.color, 1)])
+
+    with pytest.raises(ValueError, match="strictly increasing"):
+        state.validate_invariants()
+
+
+def test_canonical_small_fixture_matches_expected_trace() -> None:
+    fixture = json.loads((FIXTURE_DIR / "canonical_small.json").read_text())
+    config = LostCitiesConfig(**fixture["config"])
+    state = GameState.new_game_from_deck(fixture["initial_deck"], config)
+
+    for step in fixture["steps"]:
+        if step["action"] is not None:
+            state.apply_unified_action(step["action"])
+        assert state.phase == step["phase"]
+        assert state.current_player == step["current_player"]
+        assert state.turn_count == step["turn_count"]
+        assert state.terminal is step["terminal"]
+        assert state.score_diff(0) == step["score_diff_player0"]
+        assert state.unified_legal_mask() == step["legal_mask"]
+        state.validate_invariants()
+
+
+def test_random_games_preserve_python_core_invariants() -> None:
+    config = LostCitiesConfig(
+        n_colors=3,
+        n_ranks=5,
+        min_rank=2,
+        n_handshakes=1,
+        hand_size=5,
+    )
+    for seed in range(128):
+        state = GameState.new_game(config, seed=seed)
+        rng = random.Random(seed ^ 0x5EED)
+        steps = 0
+        while not state.terminal:
+            state.validate_invariants()
+            legal = [
+                index
+                for index, is_legal in enumerate(state.unified_legal_mask())
+                if is_legal
+            ]
+            state.apply_unified_action(rng.choice(legal))
+            steps += 1
+            assert steps < 1000
+        state.validate_invariants()
+
+
+def test_same_seed_and_action_sequence_are_deterministic() -> None:
+    config = LostCitiesConfig(seed=1234)
+    left = GameState.new_game(config)
+    right = GameState.new_game(config)
+
+    while True:
+        assert left.to_snapshot() == right.to_snapshot()
+        if left.terminal:
+            break
+
+        action = next(
+            index for index, is_legal in enumerate(left.unified_legal_mask()) if is_legal
+        )
+        left.apply_unified_action(action)
+        right.apply_unified_action(action)