fix: refresh buttons use "now" as to-date for queries

Instead of calling refetch() with stale time params, the refresh
buttons now set a toOverride state to new Date().toISOString(). This
flows into the query key, triggering a fresh fetch with the current
time as the upper bound. Both useApplicationLogs and useAgentEvents
hooks accept an optional toOverride parameter.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

ui/src/api/queries/agents.ts

@@ -19,15 +19,16 @@ export function useAgents(status?: string, application?: string) {
   });
 }
 
-export function useAgentEvents(appId?: string, agentId?: string, limit = 50) {
+export function useAgentEvents(appId?: string, agentId?: string, limit = 50, toOverride?: string) {
   const refetchInterval = useRefreshInterval(15_000);
   return useQuery({
-    queryKey: ['agents', 'events', appId, agentId, limit],
+    queryKey: ['agents', 'events', appId, agentId, limit, toOverride],
     queryFn: async () => {
       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));
       const res = await fetch(`${config.apiBaseUrl}/agents/events-log?${params}`, {
         headers: {