chore(release): prepare v0.3.1

tests/release/test_release_contracts.py

@@ -58,8 +58,8 @@ def test_release_version_and_migration_contract_has_current_head_0031():
         for path in (REPO / "app/db/alembic/versions").glob("*.py")
         if path.name != "__init__.py"
     )
-    assert 'version = "0.3.0"' in project
-    assert 'app_version: str = "0.3.0"' in config
+    assert 'version = "0.3.1"' in project
+    assert 'app_version: str = "0.3.1"' in config
     assert len(migrations) == 31
     assert migrations[-1].startswith("20260913_0031_")
 
@@ -85,7 +85,7 @@ def test_operations_separate_publication_deployment_migration_and_db_rollback():
         "Image rollback is **not** database rollback",
         "read-only root filesystem",
         "10001:10001",
-        "PortfolioHub v0.3.0 container contract",
+        "PortfolioHub v0.3.1 container contract",
         "v0.2.1 includes migration `0030`",
         "trex-web v0.2.3 displays `strategy_nick`",
     ):

tests/release/test_ruff_ratchet.py

@@ -0,0 +1,24 @@
+from scripts.ruff_ratchet import BASELINE_BY_RULE, BASELINE_TOTAL, baseline_regressions
+
+
+def _diagnostics(**counts: int) -> list[dict[str, str]]:
+    return [{"code": code} for code, count in counts.items() for _ in range(count)]
+
+
+def test_exact_baseline_passes() -> None:
+    diagnostics = _diagnostics(**BASELINE_BY_RULE)
+    assert len(diagnostics) == BASELINE_TOTAL
+    assert baseline_regressions(diagnostics) == []
+
+
+def test_new_rule_fails_from_zero_baseline() -> None:
+    assert baseline_regressions([{"code": "E501"}]) == ["E501: 1 > 0"]
+
+
+def test_existing_rule_increase_fails() -> None:
+    diagnostics = _diagnostics(I001=BASELINE_BY_RULE["I001"] + 1)
+    assert baseline_regressions(diagnostics) == ["I001: 91 > 90"]
+
+
+def test_reduced_debt_passes() -> None:
+    assert baseline_regressions(_diagnostics(I001=1, F401=1)) == []