fix(rectification): collect dated events, then distinguish with conflict probes

Empty ledgers stay in natural-language collection. After the first dated
event, dasha conflict probes reverse-infer 前事 and block offer until
answered. Unique-minute confirmation stays closed at a representative
time; adopt reverse-verifies remaining probes. Records BUG-348–351.

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_rectification_refinement_packet.py

@@ -269,6 +269,7 @@ class RefinementPacketTest(unittest.TestCase):
         self.assertNotIn("热情冲动", encoded)
         self.assertIn("事件吻合率", str(packet["event_fit_rate"]))
         self.assertFalse(packet["event_fit_rate"]["unique_minute_claim"])
+        self.assertEqual(packet["discriminating_event_probes"], [])
 
     def test_decision_receipt_downgrades_confidence_on_dasha_conflict(self):
         request = request_events()