Show configured metrics retention (Refs #141)

tests/unit/ui-metrics-page.test.ts

@@ -54,6 +54,7 @@ function report(): MetricsData {
     const summary = { observed: 10, active: 5, idle: 5, unknown: 2, playerHours: 20 };
     return {
         days: 7,
+        metricsKeepDays: 31,
         since: now - 7 * 86400000,
         now,
         firstRetainedSampleAt: now - 14 * 86400000,
@@ -116,6 +117,25 @@ function scope(search: string, stateSearch?: string) {
 }
 beforeEach(() => scope(''));
 
+it.each([
+    [31, 'for 31 days'],
+    [90, 'for 90 days'],
+    [1, 'for 1 day'],
+    [0, 'indefinitely']
+] as const)(
+    'shows configured occupancy retention of %i days in About this report',
+    (metricsKeepDays, expected) => {
+        const body = render(MetricsPage, {
+            props: { data: { ...report(), metricsKeepDays, user: null, setupRequired: false } }
+        })
+            .body.replace(/<!--[\s\S]*?-->/g, '')
+            .replace(/\s+/g, ' ');
+        const about = body.slice(body.indexOf('About this report'));
+        expect(about).toContain(`Occupancy history is retained ${expected};`);
+        expect(about).toContain('saved match retention is configured separately');
+    }
+);
+
 it('shows Provisioning outcomes and readiness with a policy link, even without occupancy', () => {
     const data = report();
     const section = render(MetricsAutoscaling, { props: { metrics: data.autoscaling } }).body;