feat(analytics): Umami integration with per-port admin settings

Adds /[portSlug]/website-analytics dashboard page (pageviews, top
pages, top referrers) and a per-port admin config UI for the
Umami URL / website-ID / API token. Settings live in system_settings
keyed per-port so a future second port has its own Umami account.
Adds a website glance tile to the main dashboard, a server-side
test-credentials endpoint, and a stable cache key for the active-
visitor poll so React Query doesn't fragment the cache per range.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/admin/website-analytics/umami-test-button.tsx

@@ -0,0 +1,67 @@
+'use client';
+
+import { useState } from 'react';
+import { Loader2, CheckCircle2, XCircle } from 'lucide-react';
+import { toast } from 'sonner';
+
+import { Button } from '@/components/ui/button';
+import { apiFetch } from '@/lib/api/client';
+
+interface TestResponse {
+  ok: boolean;
+  visitors?: number;
+  error?: string;
+}
+
+/**
+ * Hits POST /api/v1/admin/umami/test which calls Umami's `/api/websites/:id/
+ * active` to verify auth + websiteId in one request. On success, shows the
+ * live visitor count as proof we got real data back.
+ */
+export function UmamiTestButton() {
+  const [pending, setPending] = useState(false);
+  const [result, setResult] = useState<TestResponse | null>(null);
+
+  async function runTest() {
+    setPending(true);
+    setResult(null);
+    try {
+      const res = await apiFetch<{ data: TestResponse }>('/api/v1/admin/umami/test', {
+        method: 'POST',
+      });
+      setResult(res.data);
+      if (res.data.ok) {
+        toast.success(`Umami reachable - ${res.data.visitors ?? 0} active visitor(s) right now`);
+      } else {
+        toast.error(res.data.error ?? 'Umami test failed');
+      }
+    } catch (err) {
+      const message = err instanceof Error ? err.message : 'Test failed';
+      setResult({ ok: false, error: message });
+      toast.error(message);
+    } finally {
+      setPending(false);
+    }
+  }
+
+  return (
+    <div className="flex items-center gap-3">
+      {result &&
+        (result.ok ? (
+          <span className="flex items-center text-xs text-green-600">
+            <CheckCircle2 className="mr-1 h-3.5 w-3.5" />
+            Connected ({result.visitors ?? 0} active)
+          </span>
+        ) : (
+          <span className="flex items-center text-xs text-destructive">
+            <XCircle className="mr-1 h-3.5 w-3.5" />
+            {result.error ?? 'Failed'}
+          </span>
+        ))}
+      <Button type="button" size="sm" variant="outline" onClick={runTest} disabled={pending}>
+        {pending ? <Loader2 className="mr-2 h-3.5 w-3.5 animate-spin" /> : null}
+        Test connection
+      </Button>
+    </div>
+  );
+}