fix(rectification): anchor candidate windows to civil dates across midnight

Carry explicit local date intervals instead of inferring the day from clock
order. Cluster width, delivery, adoption, and reports keep the actual civil
date; adopted date is stored separately from the reported birth_date.

Algorithm identity is scoring-9 / spec-v5. Scoring weights, confirmation
thresholds, and Skill version are unchanged. Isolated Linux final-3 gates
passed; four pre-existing Python failures remain. This is not a production
release.

tests/test_rectification_relative_support.py

@@ -19,8 +19,8 @@ def _row(time: str, score: float) -> dict:
 class RelativeSupportScaleTest(unittest.TestCase):
     def test_holdout_gate_keeps_proportional_default(self) -> None:
         self.assertEqual(POLICY_VERSION, "rectification-candidate-policy-v3")
-        # Cross-midnight date fix: scoring identity -7 -> -8, not a prior/policy change.
-        self.assertEqual(ALGORITHM_VERSION, "rectification-v5-matrix-scoring-8")
+        # Explicit date windows: scoring identity -8 -> -9, not a prior/policy change.
+        self.assertEqual(ALGORITHM_VERSION, "rectification-v5-matrix-scoring-9")
         self.assertEqual(RELATIVE_SUPPORT_MODE, "proportional")
 
     def test_offset_top_two_lead_is_at_least_proportional(self) -> None: