refactor(frontend): split 7 oversized pages into feature co-location

Per guide ch.7 page split pattern (skeleton orchestrates, private
components live in features/<domain>/):
- InstancePage 1716->328, UsersPage 1309->240, TicketsPage 1076->195,
  TicketDetailPage 911->287, QueriesPage 883->479, LdapConfigPage 860->393,
  WorkflowPage 852->194
- new feature modules: datasource/ rbac/ ticket/ query/ system/ldap/
  governance/workflow/ (components + hooks + types + utils)
- stable keys replace index keys in dynamic lists; polling intervals
  and toast call sites preserved 1:1 (verified by agents)
- filter/pagination state moved to URL query via new useQueryState hook
  (Instance/Users/Tickets/AuditLogs pages): refresh/share/back-button
  restore state; composite updates applied atomically
- permission pure functions extracted to lib/permissions.ts (used by
  useAuth + useLogin); page-size audit: 0 pages over 700-line budget

frontend/src/features/ticket/components/TicketPagination.tsx

@@ -0,0 +1,59 @@
+/**
+ * 工单分页 — 页码窗口(最多展示 5 页)与上/下一页控制
+ * 可见性由父组件控制(仅 totalPages > 1 时渲染)
+ */
+
+interface TicketPaginationProps {
+  page: number;
+  total: number;
+  totalPages: number;
+  /** 页码跳转(父级写入 URL query) */
+  onPageChange: (page: number) => void;
+}
+
+export function TicketPagination({ page, total, totalPages, onPageChange }: TicketPaginationProps) {
+  return (
+    <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3 px-4 py-4 border-t border-[var(--dg-border)]">
+      <span className="text-sm text-[var(--dg-text-muted)]">共 {total} 条</span>
+      <div className="flex gap-1 overflow-x-auto">
+        <button
+          disabled={page <= 1}
+          onClick={() => onPageChange(page - 1)}
+          className="dg-btn dg-btn-ghost dg-btn-sm disabled:opacity-50"
+        >
+          上一页
+        </button>
+        {Array.from({ length: Math.min(totalPages, 5) }, (_, i) => {
+          let p: number;
+          if (totalPages <= 5) {
+            p = i + 1;
+          } else if (page <= 3) {
+            p = i + 1;
+          } else if (page >= totalPages - 2) {
+            p = totalPages - 4 + i;
+          } else {
+            p = page - 2 + i;
+          }
+          return (
+            <button
+              key={p}
+              onClick={() => onPageChange(p)}
+              className={`dg-btn dg-btn-sm dg-btn-ghost ${
+                p === page ? 'bg-blue-500 text-white hover:bg-blue-500' : ''
+              }`}
+            >
+              {p}
+            </button>
+          );
+        })}
+        <button
+          disabled={page >= totalPages}
+          onClick={() => onPageChange(page + 1)}
+          className="dg-btn dg-btn-ghost dg-btn-sm disabled:opacity-50"
+        >
+          下一页
+        </button>
+      </div>
+    </div>
+  );
+}