Fix PostgreSQL schema init: commit DDL before ALTER migrations.

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

strategy/strategy_db.py

@@ -149,6 +149,7 @@ def init_strategy_tables(conn) -> None:
         CTP_SIM_POSITIONS_SQL,
     ):
         conn.execute(sql)
+    conn.commit()
     try:
         conn.execute("ALTER TABLE trend_pullback_plans ADD COLUMN period TEXT DEFAULT '15m'")
     except Exception: