feat(api): 集群列表读改走 informer 缓存，审核队列、我的提交与备份列表改为服务端分页筛选并一次批量查构建，面板三页跟进

internal/store/migrations/0031_list_paging_indexes.sql

@@ -0,0 +1,11 @@
+-- The lists people page through read newest first with id breaking ties: the
+-- admin submission queue across every user, and the backups list across every
+-- server, one former owner's worlds, or one server's archives. Each index lets a
+-- page read its own rows instead of sorting the whole table on every request.
+CREATE INDEX image_submissions_created_idx ON image_submissions (created_at DESC, id DESC);
+CREATE INDEX world_backups_present_idx ON world_backups (created_at DESC, id DESC)
+  WHERE status = 'present';
+CREATE INDEX world_backups_server_present_idx ON world_backups (server_name, created_at DESC, id DESC)
+  WHERE status = 'present';
+CREATE INDEX world_backups_former_owner_present_idx ON world_backups (former_owner, created_at DESC, id DESC)
+  WHERE status = 'present';