Show fresh player capacity on Fleet cards

src/lib/server/fleet/player-capacity.ts

@@ -0,0 +1,18 @@
+import type { PlayerCapacityObservation } from '../../server-capacity.js';
+import { monitoringStatus } from './health-observations.js';
+import { MonitoringSnapshot } from './monitoring-snapshot.js';
+
+/** Read only the accepted, current-instance sample; never dispatch a probe. */
+export function observedPlayerCapacity(server: string, snapshot: MonitoringSnapshot): PlayerCapacityObservation {
+    const game = monitoringStatus(server, snapshot)?.game;
+    const capacity = game?.result.ok ? game.result.status.capacity : null;
+    return typeof capacity === 'number' && Number.isSafeInteger(capacity) && capacity > 0
+        ? { capacity, capacity_observed_at: game!.observedAt }
+        : { capacity: null, capacity_observed_at: null };
+}
+
+/** One joined identity read for a fleet, or a single server on a detail route. */
+export function playerCapacityReader(serverName?: string) {
+    const snapshot = new MonitoringSnapshot(serverName);
+    return (server: string) => observedPlayerCapacity(server, snapshot);
+}