feat: harden rectification candidate validation

tests/test_rectification_diagnostics_clusters.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import unittest
+
+from scripts.rectification.diagnostics_service import run_diagnostics
+
+
+def row(time: str, score: float) -> dict:
+    return {"time": time, "score": score, "evidence": [], "missing_layers": []}
+
+
+def diagnostics(rows: list[dict]) -> dict:
+    return run_diagnostics({"events": []}, rows, {"date_sensitivity": [], "matrix": {}})
+
+
+class RectificationDiagnosticsClustersTest(unittest.TestCase):
+    def test_primary_cluster_joins_adjacent_minutes_across_midnight(self):
+        result = diagnostics([
+            row("23:59", 100),
+            row("12:00", 98),
+            row("00:00", 99),
+        ])
+
+        self.assertEqual(result["neighbor_support_minutes"], 2)
+        self.assertEqual(result["candidate_splits"][0]["left_cluster"], {
+            "start": "23:59",
+            "end": "00:00",
+        })
+        self.assertEqual(result["candidate_splits"][0]["right_cluster"], {
+            "start": "12:00",
+            "end": "12:00",
+        })
+
+    def test_primary_cluster_keeps_ordinary_daytime_gaps_separate(self):
+        result = diagnostics([
+            row("05:13", 100),
+            row("05:14", 99),
+            row("05:16", 98),
+        ])
+
+        self.assertEqual(result["neighbor_support_minutes"], 2)
+        self.assertEqual(result["candidate_splits"][0]["left_cluster"], {
+            "start": "05:13",
+            "end": "05:14",
+        })
+        self.assertEqual(result["candidate_splits"][0]["right_cluster"], {
+            "start": "05:16",
+            "end": "05:16",
+        })
+
+
+if __name__ == "__main__":
+    unittest.main()