Raise coverage threshold to 95% and expand test coverage

- pyproject.toml: fail_under 80 → 95
- test_alpha: +79 lines
- test_cli_workflow: +226 lines
- test_derived: +121 lines
- test_downloader_contracts: +169 lines
- test_features: +16 lines
- test_minute_downloader: +81 lines
- test_portfolio: +208 lines

tests/test_features.py

@@ -7,6 +7,7 @@ import pandas as pd
 import pytest
 
 from pipeline.features.compute import compute_feature, validate_feature_frame
+from pipeline.features.compute import read_feature_frames
 from pipeline.features.library.minute_daily_summary import MinuteDailySummaryFeature
 from pipeline.features.registry import (
     available_features,
@@ -99,6 +100,21 @@ def test_legacy_feature_compute_matches_canonical_derived_compute():
     pd.testing.assert_frame_equal(legacy_feature, canonical_derived)
 
 
+def test_read_feature_frames_delegates_to_derived_validation(tmp_path):
+    feature = pd.DataFrame({
+        "symbol_id": ["sh600000"],
+        "date": ["2024-01-02 15:00:00"],
+        "toy_feature": [1.5],
+    })
+    feature_path = tmp_path / "feature.pq"
+    feature.to_parquet(feature_path, index=False)
+
+    [result] = read_feature_frames([feature_path])
+
+    assert result["date"].tolist() == [pd.Timestamp("2024-01-02")]
+    assert result["toy_feature"].tolist() == [1.5]
+
+
 def test_load_external_feature_module_and_filter_params(tmp_path):
     module_path = tmp_path / "external_feature.py"
     module_path.write_text(textwrap.dedent('''