feat(ui): replace useAgentEvents with useInfiniteAgentEvents

Cursor-paginated timeline stream matching the new /agents/events
endpoint. Consumers (AgentHealth, AgentInstance) updated in
follow-up commits.

ui/src/api/queries/agents.ts

@@ -3,6 +3,7 @@ import { config } from '../../config';
 import { useAuthStore } from '../../auth/auth-store';
 import { useEnvironmentStore } from '../environment-store';
 import { useRefreshInterval } from './use-refresh-interval';
+import { useInfiniteStream, type UseInfiniteStreamResult } from '../../hooks/useInfiniteStream';
 
 export function useAgents(status?: string, application?: string) {
   const environment = useEnvironmentStore((s) => s.environment);
@@ -31,18 +32,45 @@ export function useAgents(status?: string, application?: string) {
   });
 }
 
-export function useAgentEvents(appId?: string, agentId?: string, limit = 50, toOverride?: string) {
+export interface AgentEventResponse {
+  id: number;
+  instanceId: string;
+  applicationId: string;
+  eventType: string;
+  detail: string;
+  timestamp: string;
+}
+
+interface AgentEventPageResponse {
+  data: AgentEventResponse[];
+  nextCursor: string | null;
+  hasMore: boolean;
+}
+
+export interface UseInfiniteAgentEventsArgs {
+  appId?: string;
+  agentId?: string;
+  isAtTop: boolean;
+  pageSize?: number;
+}
+
+export function useInfiniteAgentEvents(
+  args: UseInfiniteAgentEventsArgs,
+): UseInfiniteStreamResult<AgentEventResponse> {
   const environment = useEnvironmentStore((s) => s.environment);
-  const refetchInterval = useRefreshInterval(15_000);
-  return useQuery({
-    queryKey: ['agents', 'events', environment, appId, agentId, limit, toOverride],
-    queryFn: async () => {
+  const pageSize = args.pageSize ?? 50;
+
+  return useInfiniteStream<AgentEventResponse>({
+    queryKey: ['agents', 'events', 'infinite', environment ?? '', args.appId ?? '', args.agentId ?? '', pageSize],
+    enabled: !!environment,
+    isAtTop: args.isAtTop,
+    fetchPage: async (cursor) => {
       const token = useAuthStore.getState().accessToken;
       const params = new URLSearchParams();
-      if (appId) params.set('appId', appId);
-      if (agentId) params.set('agentId', agentId);
-      if (toOverride) params.set('to', toOverride);
-      params.set('limit', String(limit));
+      if (args.appId) params.set('appId', args.appId);
+      if (args.agentId) params.set('agentId', args.agentId);
+      if (cursor) params.set('cursor', cursor);
+      params.set('limit', String(pageSize));
       const res = await fetch(
         `${config.apiBaseUrl}/environments/${encodeURIComponent(environment!)}/agents/events?${params}`,
         {
@@ -52,9 +80,8 @@ export function useAgentEvents(appId?: string, agentId?: string, limit = 50, toO
           },
         });
       if (!res.ok) throw new Error('Failed to load agent events');
-      return res.json();
+      const page: AgentEventPageResponse = await res.json();
+      return { data: page.data, nextCursor: page.nextCursor, hasMore: page.hasMore };
     },
-    enabled: !!environment,
-    refetchInterval,
   });
 }