fixed reasoning

backend/app/db/migrate.py

@@ -21,6 +21,12 @@ def run_migrations() -> None:
                     )
                 )
 
+    if "messages" in inspector.get_table_names():
+        columns = {col["name"] for col in inspector.get_columns("messages")}
+        with engine.begin() as conn:
+            if "reasoning_json" not in columns:
+                conn.execute(text("ALTER TABLE messages ADD COLUMN reasoning_json TEXT"))
+
     if "pomodoro_cycles" not in inspector.get_table_names():
         return