fix: FormData not JSON serializable in validation handler, dashboard log to INFO

app/admin/router.py

@@ -53,7 +53,7 @@ async def dashboard(request: Request):
         )
         total_revenue = float((await session.execute(rev_stmt)).scalar_one())
 
-    logger.debug(
+    logger.info(
         "Dashboard data: users={}/{} tariffs={} servers={}/{} payments={}/{} revenue={}",
         active_users, total_users, total_tariffs,
         active_servers, total_servers,