Add configurable history and storage retention policies

src/lib/server/fleet/metrics.ts

@@ -1,3 +1,4 @@
+import { fleetSettings } from '../settings.js';
 import { db } from '../db/index.js';
 import { ONLINE_MAX_MS } from '../../server-freshness.js';
 import { parseMetricsQuery, type HeatmapCell, type MapMetrics, type MetricPoint, type MetricsData,
@@ -18,7 +19,8 @@ export function recordMetrics(samples: MetricSample[], at = Date.now()): void {
     handle.transaction(() => {
         const insert = handle.prepare('INSERT OR REPLACE INTO metric_samples (at, server, game, map, players, capacity) VALUES (?, ?, ?, ?, ?, ?)');
         for (const s of samples) insert.run(at, s.server, s.game, s.map, s.players, s.capacity);
-        handle.prepare('DELETE FROM metric_samples WHERE at < ?').run(at - 31 * 86400_000);
+        const days = fleetSettings().metricsKeepDays;
+        if (days) handle.prepare('DELETE FROM metric_samples WHERE at < ?').run(at - days * 86400_000);
     })();
 }