Scaffold homelab-monitor: Fastify API + React dashboard + CI

Vertical slice for Phase 1 (v1-dashboard milestone): Proxmox collector,
SQLite storage, local auth, and a dashboard UI showing host/container
status cards. Config-driven collector registry so future data sources
(SSH-based hosts, Zabbix, network discovery) plug in without rewiring.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/src/App.tsx

@@ -0,0 +1,24 @@
+import { useEffect, useState } from "react";
+import { me } from "./api";
+import { Login } from "./pages/Login";
+import { Dashboard } from "./pages/Dashboard";
+
+export default function App() {
+  const [username, setUsername] = useState<string | null>(null);
+  const [checked, setChecked] = useState(false);
+
+  useEffect(() => {
+    me()
+      .then((r) => setUsername(r.username))
+      .catch(() => setUsername(null))
+      .finally(() => setChecked(true));
+  }, []);
+
+  if (!checked) return null;
+
+  if (!username) {
+    return <Login onLoggedIn={() => me().then((r) => setUsername(r.username))} />;
+  }
+
+  return <Dashboard username={username} onLoggedOut={() => setUsername(null)} />;
+}