优化账号分组调度索引

backend/migrations/150_account_group_scheduler_indexes_notx.sql

@@ -0,0 +1,5 @@
+CREATE INDEX CONCURRENTLY IF NOT EXISTS idx_account_groups_group_priority_account
+    ON account_groups (group_id, priority, account_id);
+
+CREATE INDEX CONCURRENTLY IF NOT EXISTS idx_account_groups_account_priority_group
+    ON account_groups (account_id, priority, group_id);