fix: grandfather pre-cutover stop episodes

alembic/versions/022_add_paper_trade_reentry_gate_reset.py

@@ -30,6 +30,22 @@ def upgrade() -> None:
             nullable=True,
         ),
     )
+    # The policy starts at this deployment. Historical NULL values mean the
+    # scanner never recorded reset observations, not that those old episodes
+    # are still active. Mark both transitions complete so only stops created
+    # after the migration can open a re-entry lock.
+    op.execute(
+        sa.text(
+            """
+            UPDATE paper_trades
+            SET reentry_gate_failed_at = closed_at,
+                reentry_gate_requalified_at = closed_at
+            WHERE status = 'closed'
+              AND close_reason = 'stop'
+              AND closed_at IS NOT NULL
+            """
+        )
+    )
 
 
 def downgrade() -> None: