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_rust_parity.py

@@ -0,0 +1,167 @@
+import json
+from pathlib import Path
+import random
+import subprocess
+
+import coolrl_lost_cities.games.classic as classic
+from coolrl_lost_cities.games.classic.game import GameState, LostCitiesConfig, build_deck
+
+
+LOST_CITIES_DIR = Path(classic.__file__).resolve().parent
+FIXTURE_DIR = LOST_CITIES_DIR / "fixtures"
+RUST_CORE_DIR = LOST_CITIES_DIR / "rust_core"
+
+
+def _run_probe(*args: str) -> dict:
+    result = subprocess.run(
+        ["cargo", "run", "--quiet", "--bin", "lost_cities_probe", "--", *args],
+        cwd=RUST_CORE_DIR,
+        check=True,
+        text=True,
+        capture_output=True,
+    )
+    return json.loads(result.stdout)
+
+
+def _python_trace(path: Path) -> dict:
+    fixture = json.loads(path.read_text())
+    config = LostCitiesConfig(**fixture["config"])
+    state = GameState.new_game_from_deck(fixture["initial_deck"], config)
+    steps = []
+    for step in fixture["steps"]:
+        action = step["action"]
+        if action is not None:
+            state.apply_unified_action(action)
+        state.validate_invariants()
+        snapshot = state.to_snapshot()
+        steps.append(
+            {
+                "action": action,
+                "phase": state.phase,
+                "current_player": state.current_player,
+                "turn_count": state.turn_count,
+                "terminal": state.terminal,
+                "pending_discarded_color": state.pending_discarded_color,
+                "score_diff_player0": state.score_diff(0),
+                "legal_mask": state.unified_legal_mask(),
+                "deck": snapshot["deck"],
+                "hands": snapshot["hands"],
+                "expeditions": snapshot["expeditions"],
+                "discards": snapshot["discards"],
+            }
+        )
+    return {"config": config.to_snapshot(), "steps": steps}
+
+
+def test_rust_default_config_matches_python_default() -> None:
+    assert _run_probe("defaults") == LostCitiesConfig().to_snapshot()
+
+
+def test_rust_fixture_trace_matches_python_core() -> None:
+    fixture_path = FIXTURE_DIR / "canonical_small.json"
+    assert _run_probe("trace", str(fixture_path)) == _python_trace(fixture_path)
+
+
+def test_rust_randomized_fixture_traces_match_python_core(tmp_path: Path) -> None:
+    config = LostCitiesConfig(
+        n_colors=3,
+        n_ranks=5,
+        min_rank=2,
+        n_handshakes=1,
+        hand_size=5,
+    )
+
+    for seed in range(12):
+        deck = build_deck(config)
+        rng = random.Random(seed)
+        rng.shuffle(deck)
+        state = GameState.new_game_from_deck(deck, config)
+        steps = [{"action": None}]
+
+        for _ in range(64):
+            if state.terminal:
+                break
+            legal = [
+                index
+                for index, is_legal in enumerate(state.unified_legal_mask())
+                if is_legal
+            ]
+            action = rng.choice(legal)
+            state.apply_unified_action(action)
+            steps.append({"action": action})
+
+        fixture_path = tmp_path / f"parity_{seed}.json"
+        fixture_path.write_text(
+            json.dumps(
+                {
+                    "config": config.to_snapshot(),
+                    "initial_deck": [card.to_snapshot() for card in deck],
+                    "steps": steps,
+                }
+            )
+        )
+        assert _run_probe("trace", str(fixture_path)) == _python_trace(fixture_path)
+
+
+def test_rust_engine_contract_is_checked_from_python() -> None:
+    result = _run_probe("engine")
+
+    assert result["duplicate_kind"] == "AlreadyExists"
+    assert result["missing_config_kind"] == "InvalidArgument"
+    assert result["empty_session_kind"] == "InvalidArgument"
+    assert result["unknown_session_kind"] == "NotFound"
+    assert result["invalid_observer_kind"] == "InvalidArgument"
+    assert result["invalid_observer_state_unchanged"] is True
+    assert result["invalid_observer_action_still_applies"] is True
+    assert result["phase_flow"][:2] == [
+        {
+            "state_version": 0,
+            "current_player": 0,
+            "observer_player": 0,
+            "phase": "card",
+            "terminal": False,
+        },
+        {
+            "state_version": 1,
+            "current_player": 0,
+            "observer_player": 0,
+            "phase": "draw",
+            "terminal": False,
+        },
+    ]
+    assert result["phase_flow"][2]["state_version"] == 2
+    assert result["stale_kind"] == "FailedPrecondition"
+    assert result["end_session_counts"] == [1, 0]
+    assert result["off_turn_legal_empty"] is True
+    assert result["full_session_terminal_reward_matches"] is True
+    assert result["full_session_final_scores_match"] is True
+    assert result["terminal_reject_kind"] == "FailedPrecondition"
+    assert result["deterministic_match"] is True
+
+
+def test_rust_grpc_contract_is_checked_from_python() -> None:
+    result = _run_probe("grpc")
+
+    assert result == {
+        "round_trip_phase": "card",
+        "opponent_legal_empty": True,
+        "stale_code": "FailedPrecondition",
+        "invalid_observer_code": "InvalidArgument",
+        "invalid_observer_state_unchanged": True,
+        "ended_session_code": "NotFound",
+    }
+
+
+def test_rust_core_has_no_native_tests_left() -> None:
+    rust_files = [
+        path
+        for path in (RUST_CORE_DIR / "src").rglob("*.rs")
+        if "target" not in path.parts
+    ]
+    for path in rust_files:
+        text = path.read_text()
+        assert "#[test]" not in text
+        assert "#[tokio::test" not in text
+
+    tests_dir = RUST_CORE_DIR / "tests"
+    assert not list(tests_dir.glob("*.rs"))