feat: add fundamentals parity reporting

tests/unit/test_fundamentals_derivation.py

@@ -104,6 +104,22 @@ def test_net_debt_leverage_and_share_dilution():
     assert d.metrics["share_count_change_yoy"].value == pytest.approx(-10.0, abs=1e-6)
 
 
+def test_split_suspect_share_move_suppresses_share_and_eps_comparisons():
+    rows = _two_years()
+    for row in rows:
+        if row.fiscal_year == 2026:
+            row.shares_outstanding = 2000  # +100% resembles an unadjusted 2-for-1 split
+
+    d = fd.derive(rows)
+
+    for key in ("share_count_change_yoy", "eps_growth_yoy"):
+        series = d.metrics[key]
+        assert series.value is None
+        assert series.history[-1].value is None
+        assert "possible split" in series.caveat
+    assert d.metrics["revenue_growth_yoy"].value == pytest.approx(10.0)
+
+
 def test_valuation_inputs():
     d = fd.derive(_two_years())
     # TTM diluted EPS FY2026 = 1.1+1.21+1.32+1.43 = 5.06