tests: add a recipe to re-record parity traces

tests/test_parity.py

@@ -1,14 +1,10 @@
-from pathlib import Path
-
 import pytest
-from game_trace import run_trace
-
-FIXTURES = Path(__file__).parent / "fixtures"
+from game_trace import FIXTURES, SEEDS, run_trace
 
 
-@pytest.mark.parametrize("seed", ["alpha", "beta", "gamma"])
+@pytest.mark.parametrize("seed", SEEDS)
 def test_gameplay_matches_recorded_trace(seed: str) -> None:
-    # The fixtures were recorded before the word lists moved to data files;
-    # stock data must reproduce them exactly, RNG stream included.
+    # The fixtures pin down gameplay, RNG stream included. When a change is
+    # meant to alter gameplay, re-record them with `just record-traces`.
     expected = (FIXTURES / f"parity_{seed}.txt").read_text().splitlines()
     assert run_trace(seed) == expected