Improve timestamp handling and event navigation

web/src/components/AgentsBrowser.tsx

@@ -5,8 +5,9 @@ import { useMemo, useState } from "react";
 
 import { AgentFeatures } from "@/components/AgentFeatures";
 import { LabelChips } from "@/components/Labels";
+import { DateTime } from "@/components/TimeZoneControls";
 import type { Agent, CheckState } from "@/lib/api";
-import { fmtDate, statusBadgeClass } from "@/lib/format";
+import { statusBadgeClass } from "@/lib/format";
 
 type CheckStatus = CheckState["status"];
 type CheckCounts = Record<CheckStatus, number>;
@@ -104,7 +105,9 @@ export function AgentsBrowser({ rows: initialRows }: { rows: AgentRow[] }) {
                 <Td>
                   <AgentStatus status={a.status} checks={checks} />
                 </Td>
-                <Td>{fmtDate(a.last_seen_at)}</Td>
+                <Td>
+                  <DateTime iso={a.last_seen_at} />
+                </Td>
                 <Td>
                   <AgentFeatures features={a.features} />
                 </Td>