refactor web pagination and add partitioned events, flap/timeout showcase agents

web/src/lib/pagination.ts

@@ -0,0 +1,23 @@
+export const PAGE_SIZE_OPTIONS = [10, 50, 100] as const;
+export type PageSize = (typeof PAGE_SIZE_OPTIONS)[number];
+export const DEFAULT_PAGE_SIZE: PageSize = 10;
+
+export function pageCountOf(total: number, pageSize: number): number {
+  return Math.max(1, Math.ceil(total / pageSize));
+}
+
+export function clampPage(page: number, pageCount: number): number {
+  if (page < 1) return 1;
+  if (page > pageCount) return pageCount;
+  return page;
+}
+
+export function paginate<T>(items: T[], page: number, pageSize: number): T[] {
+  const start = (page - 1) * pageSize;
+  return items.slice(start, start + pageSize);
+}
+
+export function normalizePageSize(value: unknown, fallback: PageSize = DEFAULT_PAGE_SIZE): PageSize {
+  const n = Number(value);
+  return (PAGE_SIZE_OPTIONS as readonly number[]).includes(n) ? (n as PageSize) : fallback;
+}