Add React UI with Vite

Dashboard, agents, goals, issues, and projects pages with sidebar
navigation. API client layer, custom hooks, and shared layout
components. Built with Vite and TypeScript.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/pages/Agents.tsx

@@ -0,0 +1,36 @@
+import { useAgents } from "../hooks/useAgents";
+import { StatusBadge } from "../components/StatusBadge";
+import { formatCents } from "../lib/utils";
+
+export function Agents() {
+  const { data: agents, loading, error } = useAgents();
+
+  return (
+    <div>
+      <h2 className="text-2xl font-bold mb-4">Agents</h2>
+      {loading && <p className="text-gray-500">Loading...</p>}
+      {error && <p className="text-red-600">{error.message}</p>}
+      {agents && agents.length === 0 && <p className="text-gray-500">No agents yet.</p>}
+      {agents && agents.length > 0 && (
+        <div className="grid gap-4">
+          {agents.map((agent) => (
+            <div key={agent.id} className="bg-white rounded-lg border border-gray-200 p-4">
+              <div className="flex items-center justify-between">
+                <div>
+                  <h3 className="font-semibold">{agent.name}</h3>
+                  <p className="text-sm text-gray-500">{agent.role}</p>
+                </div>
+                <div className="flex items-center gap-3">
+                  <span className="text-sm text-gray-500">
+                    {formatCents(agent.spentCents)} / {formatCents(agent.budgetCents)}
+                  </span>
+                  <StatusBadge status={agent.status} />
+                </div>
+              </div>
+            </div>
+          ))}
+        </div>
+      )}
+    </div>
+  );
+}