feat(random): multi-theme groundwork, locked reroll export parity, duplicate export fix, expanded diagnostics and test coverage

code/tests/test_random_full_build_determinism.py

@@ -1,9 +1,32 @@
 from __future__ import annotations
 
 import os
+import pytest
+from fastapi.testclient import TestClient
 from deck_builder.random_entrypoint import build_random_full_deck
 
 
+@pytest.fixture(scope="module")
+def client():
+    os.environ["RANDOM_MODES"] = "1"
+    os.environ["CSV_FILES_DIR"] = os.path.join("csv_files", "testdata")
+    from web.app import app
+    with TestClient(app) as c:
+        yield c
+
+
+def test_full_build_same_seed_produces_same_deck(client: TestClient):
+    body = {"seed": 4242}
+    r1 = client.post("/api/random_full_build", json=body)
+    assert r1.status_code == 200, r1.text
+    d1 = r1.json()
+    r2 = client.post("/api/random_full_build", json=body)
+    assert r2.status_code == 200, r2.text
+    d2 = r2.json()
+    assert d1.get("seed") == d2.get("seed") == 4242
+    assert d1.get("decklist") == d2.get("decklist")
+
+
 def test_random_full_build_is_deterministic_on_frozen_dataset(monkeypatch):
     # Use frozen dataset for determinism
     monkeypatch.setenv("CSV_FILES_DIR", os.path.join("csv_files", "testdata"))