swarm-ui: real hive-roster overview page

Fixes hyperhive#3223.

swarm-controller: GET /api/hives (utoipa-annotated same as /health),
serving the swarm's hive directory (name + domain) loaded once at
startup from a new SWARM_CONTROLLER_HIVES env var. The controller's
NixOS module sets it from services.hyperhive.swarm.hives, JSON-encoded
the same way hive-c0re already builds HYPERHIVE_PEERS for its own peer
list (environment.nix) — the full directory here rather than
peers-minus-self, since a swarm-level daemon has no 'self' hive to
exclude. Unset/malformed both fall back to an empty list with a
warning rather than failing startup, so /health stays answerable even
if this one env var is wrong.

swarm-ui: App.tsx's Home route fetches /api/hives and renders it
through the already-merged <Table>/<StatusChip>/<Panel> primitives —
name, domain (linking out to that hive's own gateway-routed
dashboard), and a static "configured" status chip until a real
online/stale/offline rollup exists server-side. Also gave swarm-ui a
base <a> color (theme's --blue) — base.css covers body/typography but
not links, and this is genuinely page-level rather than any one
component's concern.

Verified end to end, not just source-reading: ran the real
swarm-controller binary with SWARM_CONTROLLER_HIVES set, curled
/api/hives + /health over its actual unix socket; separately served
the real swarm-ui dist against a mock /api/hives and screenshotted the
rendered table. Also re-verified the nginx wiring evaluates (same
throwaway nixosSystem eval technique as #3212) — SWARM_CONTROLLER_HIVES
resolves to the expected JSON shape.

cargo test/clippy -p swarm-controller clean (2 tests, including a new
load_hives one covering missing/malformed/valid env var states). npm
run build + typecheck clean.

frontend/packages/swarm-ui/src/App.tsx

@@ -1,15 +1,57 @@
-// Root shell component. Real route (`/`) is still a placeholder — the
-// swarm's hive roster is the next piece of work to land into it — but
-// it now mounts inside <Shell> and uses the ui/ primitives, so that
-// page lands as a content change, not a structural one.
+// Root shell component. `/` is now the real hive-roster overview page —
+// fetches swarm-controller's `GET /api/hives` and renders it through the
+// shared primitives. Status starts as a static "configured" chip; grows
+// into a real online/stale/offline tone once a status rollup exists
+// server-side — same component, richer data later, no rebuild.
+import { useEffect, useState } from 'preact/hooks';
 import { Route, Switch } from 'wouter-preact';
 import { Shell } from './shell/Shell.js';
 import { Panel } from './ui/panel/Panel.js';
+import { StatusChip } from './ui/status-chip/StatusChip.js';
+import { Table, type TableColumn } from './ui/table/Table.js';
+
+interface Hive {
+  name: string;
+  domain: string;
+}
+
+const COLUMNS: TableColumn<Hive>[] = [
+  { key: 'name', header: 'name', render: (h) => h.name },
+  {
+    key: 'domain',
+    header: 'domain',
+    render: (h) => (
+      <a href={`https://${h.domain}/`} target="_blank" rel="noreferrer">
+        {h.domain}
+      </a>
+    ),
+  },
+  // Static "configured" tone until a swarm-wide status rollup exists —
+  // there is no data source for online/stale/offline yet, and a chip
+  // that always renders "positive" would misreport a genuinely offline
+  // hive. See StatusChip's own doc comment for the same reasoning.
+  { key: 'status', header: 'status', render: () => <StatusChip label="configured" /> },
+];
 
 function Home() {
+  const [hives, setHives] = useState<Hive[] | null>(null);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    fetch('/api/hives')
+      .then((r) => {
+        if (!r.ok) throw new Error(`http ${r.status}`);
+        return r.json() as Promise<Hive[]>;
+      })
+      .then(setHives)
+      .catch((e: unknown) => setError(String(e)));
+  }, []);
+
   return (
     <Panel title="overview">
-      <p>hive roster lands here, sequenced after this shell.</p>
+      {error ? <p>failed to load the hive roster: {error}</p> : null}
+      {!error && hives === null ? <p>loading…</p> : null}
+      {hives ? <Table columns={COLUMNS} rows={hives} rowKey={(h) => h.name} /> : null}
     </Panel>
   );
 }

frontend/packages/swarm-ui/src/swarm-ui.css

@@ -5,3 +5,10 @@
    every page needs regardless of which components a route happens to
    use. */
 @import "@hive/shared/base.css";
+
+/* base.css covers body/typography but not links — every page here links
+   out (hive-roster rows to each hive's own dashboard, nav, footer…), so
+   this is genuinely page-level, not any one component's concern. */
+a {
+  color: var(--blue);
+}