fix: Activity Log — replace useInfiniteQuery with simple useQuery + cursor

The useInfiniteQuery with tRPC as-any cast wasn't passing cursors
correctly, causing no data to load on initial page visit.

Replaced with simple useQuery + manual cursor state:
- First 50 entries load immediately on mount
- "Load more" button appends next page via cursor
- Filter changes reset cursor and entries
- keepPreviousData prevents flash during pagination

Co-Authored-By: claude-flow <ruv@ruv.net>

apps/web/src/components/admin/ActivityLogClient.tsx

@@ -1,6 +1,6 @@
 "use client";
 
-import { useState, useMemo, useCallback } from "react";
+import { useState, useMemo, useCallback, useEffect } from "react";
 import Link from "next/link";
 import type { Route } from "next";
 import { trpc } from "~/lib/trpc/client.js";
@@ -209,45 +209,39 @@ export function ActivityLogClient() {
     return input;
   }, [entityType, action, userId, search, startDate, endDate]);
 
-  type AuditListPage = { items: Array<{
-    id: string;
-    entityType: string;
-    entityId: string;
-    action: string;
-    changes: unknown;
-    createdAt: Date;
-    source: string | null;
-    entityName: string | null;
-    summary: string | null;
-    user: { id: string; name: string | null; email: string } | null;
-  }>; nextCursor?: string };
+  const [cursor, setCursor] = useState<string | undefined>(undefined);
+  const [allEntries, setAllEntries] = useState<any[]>([]);
+  const [hasNextPage, setHasNextPage] = useState(false);
 
-  const {
-    data,
-    isLoading,
-    fetchNextPage,
-    hasNextPage,
-    isFetchingNextPage,
-    // Keep as any to avoid tRPC TS depth limits with useInfiniteQuery
-  } = (trpc.auditLog.list.useInfiniteQuery as any)(
-    queryInput,
-    {
-      getNextPageParam: (lastPage: AuditListPage) => lastPage.nextCursor ?? undefined,
-      initialCursor: undefined,
-      staleTime: 30_000,
-    },
-  ) as {
-    data: { pages: AuditListPage[] } | undefined;
-    isLoading: boolean;
-    fetchNextPage: () => void;
-    hasNextPage: boolean;
-    isFetchingNextPage: boolean;
-  };
+  const { data, isLoading, isFetching } = (trpc.auditLog.list as any).useQuery(
+    { ...queryInput, ...(cursor ? { cursor } : {}) },
+    { staleTime: 30_000, keepPreviousData: true },
+  ) as { data: { items: any[]; nextCursor?: string } | undefined; isLoading: boolean; isFetching: boolean };
 
-  const allEntries = useMemo(() => {
-    if (!data) return [];
-    return data.pages.flatMap((page) => page.items);
-  }, [data]);
+  // Append new page results
+  useEffect(() => {
+    if (!data) return;
+    if (!cursor) {
+      // First page or filter change — replace
+      setAllEntries(data.items);
+    } else {
+      // Subsequent page — append
+      setAllEntries((prev) => [...prev, ...data.items]);
+    }
+    setHasNextPage(!!data.nextCursor);
+  }, [data, cursor]);
+
+  // Reset cursor when filters change
+  useEffect(() => {
+    setCursor(undefined);
+    setAllEntries([]);
+  }, [entityType, action, userId, search, startDate, endDate]);
+
+  function loadMore() {
+    if (data?.nextCursor) {
+      setCursor(data.nextCursor);
+    }
+  }
 
   const toggleExpand = useCallback((id: string) => {
     setExpandedId((prev) => (prev === id ? null : id));
@@ -462,11 +456,11 @@ export function ActivityLogClient() {
         {hasNextPage && (
           <div className="flex justify-center pt-4">
             <button
-              onClick={() => fetchNextPage()}
-              disabled={isFetchingNextPage}
+              onClick={loadMore}
+              disabled={isFetching}
               className="rounded-lg border border-gray-300 bg-white px-6 py-2 text-sm font-medium text-gray-700 hover:bg-gray-50 disabled:opacity-50 dark:border-slate-600 dark:bg-slate-800 dark:text-gray-300 dark:hover:bg-slate-700"
             >
-              {isFetchingNextPage ? "Loading..." : "Load more"}
+              {isFetching ? "Loading..." : "Load more"}
             </button>
           </div>
         )}