mechanic: move word lists to data files

The word lists (monsters, spells, equipment, races, classes, titles and
so on) now live in pqcli/data/*.json instead of pqcli/config.py. A
GameData object loaded at startup is passed to the simulation and UIs.

Users can replace any list by putting NAME.json in
$XDG_CONFIG_HOME/pqcli/data/ or a directory given with --data-dir.
--dump-data DIR copies the built-in files out for editing. Malformed
files are reported and pqcli exits before starting the UI.

Combat task descriptions come from the new combat_verbs list, with
{target} standing for the enemy. The built-in list holds only "Executing
{target}", and a single verb consumes no random roll, so stock gameplay
is unchanged. Recorded traces in tests/fixtures pin this down.

Monster, Race and Class stay in pqcli.config so existing saves still
load.

Resolves #3

tests/test_game_data.py

@@ -0,0 +1,182 @@
+import datetime
+import json
+import pickle
+import typing as T
+from pathlib import Path
+
+import pytest
+
+from pqcli import random
+from pqcli.config import Class, Monster, Race, StatType
+from pqcli.game_data import (
+    DATA_FILES,
+    DataError,
+    GameData,
+    dump_builtin_data,
+    load_game_data,
+)
+from pqcli.mechanic import Player, Stats, monster_task
+
+
+def write(directory: Path, name: str, value: T.Any) -> Path:
+    path = directory / f"{name}.json"
+    path.write_text(json.dumps(value), encoding="utf-8")
+    return path
+
+
+def test_builtin_data_loads() -> None:
+    data = load_game_data()
+    assert data.spells[0] == "Slime Finger"
+    assert data.monsters[0] == Monster("Anhkheg", 6, "chitin")
+    assert data.races[0] == Race("Half Orc", [StatType.hp_max])
+    assert data.classes[-1] == Class("Vermineer", [StatType.intelligence])
+    assert data.combat_verbs == ("Executing {target}",)
+    assert all(getattr(data, name) for name in DATA_FILES)
+
+
+def test_builtin_data_keeps_quirks() -> None:
+    data = load_game_data()
+    names = [monster.name for monster in data.monsters]
+    assert names.count("Rat") == 2
+    assert Monster("Neo-Otyugh", 11, "organ ") in data.monsters
+    assert any(monster.item is None for monster in data.monsters)
+
+
+def test_missing_override_dir_uses_builtin(tmp_path: Path) -> None:
+    assert load_game_data(tmp_path / "nope") == load_game_data()
+
+
+def test_override_replaces_only_that_list(tmp_path: Path) -> None:
+    write(tmp_path, "spells", ["Zap", "Bonk"])
+    write(
+        tmp_path,
+        "races",
+        [{"name": "Robot", "attr": ["STR", "hp_max", "Wisdom"]}],
+    )
+    builtin = load_game_data()
+    data = load_game_data(tmp_path)
+    assert data.spells == ("Zap", "Bonk")
+    assert data.races == (
+        Race("Robot", [StatType.strength, StatType.hp_max, StatType.wisdom]),
+    )
+    assert data.monsters == builtin.monsters
+    assert data.classes == builtin.classes
+
+
+def test_override_accepts_all_shapes(tmp_path: Path) -> None:
+    write(tmp_path, "monsters", [{"name": "Bob", "level": 0, "item": None}])
+    write(tmp_path, "weapons", [{"name": "Spoon", "quality": -1}])
+    write(tmp_path, "offense_bad", [{"name": "Soggy", "quality": -2}])
+    data = load_game_data(tmp_path)
+    assert data.monsters == (Monster("Bob", 0, None),)
+    assert data.weapons[0].name == "Spoon"
+    assert data.offense_bad[0].quality == -2
+
+
+def test_unknown_file_warns(
+    tmp_path: Path, capsys: pytest.CaptureFixture[str]
+) -> None:
+    write(tmp_path, "monster", [])
+    load_game_data(tmp_path)
+    assert "monster.json" in capsys.readouterr().err
+
+
+@pytest.mark.parametrize(
+    "name,value,message",
+    [
+        ("spells", [], "must not be empty"),
+        ("spells", {"a": 1}, "must be a list"),
+        ("spells", ["ok", 3], "[1]"),
+        ("monsters", [{"name": "Imp", "level": "2", "item": "x"}], "level"),
+        ("monsters", [{"name": "Imp", "level": True, "item": "x"}], "level"),
+        ("monsters", [{"name": "Imp", "level": 2}], "item"),
+        ("monsters", [{"name": "Imp", "level": 2, "item": 1}], "item"),
+        ("weapons", [{"name": "Spoon", "quality": 1, "x": 1}], "x"),
+        ("races", [{"name": "Elf", "attr": ["LUCK"]}], "LUCK"),
+        ("races", [{"name": "Elf", "attr": "STR"}], "attr"),
+        ("combat_verbs", ["Hitting"], "{target}"),
+    ],
+)
+def test_invalid_override_raises(
+    tmp_path: Path, name: str, value: T.Any, message: str
+) -> None:
+    write(tmp_path, name, value)
+    with pytest.raises(DataError) as excinfo:
+        load_game_data(tmp_path)
+    assert f"{name}.json" in str(excinfo.value)
+    assert message in str(excinfo.value)
+
+
+def test_malformed_json_raises(tmp_path: Path) -> None:
+    (tmp_path / "spells.json").write_text("[oops", encoding="utf-8")
+    with pytest.raises(DataError, match="spells.json"):
+        load_game_data(tmp_path)
+
+
+def test_non_utf8_raises(tmp_path: Path) -> None:
+    (tmp_path / "spells.json").write_bytes(b'["\xff"]')
+    with pytest.raises(DataError, match="spells.json"):
+        load_game_data(tmp_path)
+
+
+def test_override_dir_must_be_directory(tmp_path: Path) -> None:
+    path = write(tmp_path, "spells", ["Zap"])
+    with pytest.raises(DataError, match="not a directory"):
+        load_game_data(path)
+
+
+def test_combat_verbs_are_used(tmp_path: Path) -> None:
+    verbs = [
+        "Fighting bravely against {target}",
+        "Kicking the butt of {target}",
+    ]
+    write(tmp_path, "combat_verbs", verbs)
+    data = load_game_data(tmp_path)
+    random.seed("verbs")
+    seen = set()
+    for _ in range(200):
+        description = monster_task(data, 5, None).description
+        prefix = description.split(" ")[0]
+        assert prefix in {"Fighting", "Kicking"}
+        assert "{target}" not in description
+        seen.add(prefix)
+    assert seen == {"Fighting", "Kicking"}
+
+
+def test_dump_builtin_data_round_trips(tmp_path: Path) -> None:
+    written = dump_builtin_data(tmp_path / "out")
+    assert sorted(path.stem for path in written) == sorted(DATA_FILES)
+    assert load_game_data(tmp_path / "out") == load_game_data()
+
+
+def test_dump_builtin_data_refuses_to_overwrite(tmp_path: Path) -> None:
+    existing = write(tmp_path, "spells", ["Mine"])
+    with pytest.raises(DataError, match="spells.json"):
+        dump_builtin_data(tmp_path)
+    assert json.loads(existing.read_text()) == ["Mine"]
+    assert list(tmp_path.iterdir()) == [existing]
+
+
+def test_saved_player_survives_removed_race(tmp_path: Path) -> None:
+    data = load_game_data()
+    player = Player(
+        name="Saved",
+        birthday=datetime.datetime(2000, 1, 1),
+        race=data.races[3],
+        class_=data.classes[2],
+        stats=Stats({stat: 10 for stat in StatType}),
+    )
+    blob = pickle.dumps(player)
+
+    write(tmp_path, "races", [{"name": "Robot", "attr": ["STR"]}])
+    load_game_data(tmp_path)
+    restored = pickle.loads(blob)
+    assert restored.race == Race("Double Hobbit", [StatType.strength])
+    assert type(restored.race).__module__ == "pqcli.config"
+
+
+def test_game_data_is_immutable() -> None:
+    data = load_game_data()
+    assert isinstance(data, GameData)
+    with pytest.raises(AttributeError):
+        data.spells = ()  # type: ignore[misc]