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/App.tsx

@@ -0,0 +1,21 @@
+import { Routes, Route } from "react-router-dom";
+import { Layout } from "./components/Layout";
+import { Dashboard } from "./pages/Dashboard";
+import { Agents } from "./pages/Agents";
+import { Projects } from "./pages/Projects";
+import { Issues } from "./pages/Issues";
+import { Goals } from "./pages/Goals";
+
+export function App() {
+  return (
+    <Routes>
+      <Route element={<Layout />}>
+        <Route index element={<Dashboard />} />
+        <Route path="agents" element={<Agents />} />
+        <Route path="projects" element={<Projects />} />
+        <Route path="issues" element={<Issues />} />
+        <Route path="goals" element={<Goals />} />
+      </Route>
+    </Routes>
+  );
+}