Show configured metrics retention (Refs #141)

src/lib/metrics.ts

@@ -145,6 +145,8 @@ export interface AutoscalingMetrics {
 
 export interface MetricsData {
     days: MetricsDays;
+    /** Configured occupancy history retention; zero keeps samples indefinitely. */
+    metricsKeepDays: number;
     since: number;
     now: number;
     /** Retained sample timestamps describe collection, not gameplay freshness. */

src/lib/server/fleet/metrics.ts

@@ -507,6 +507,7 @@ export function readMetrics(input: MetricsDays | MetricsQuery, now = Date.now())
     };
     return {
         days,
+        metricsKeepDays: fleetSettings().metricsKeepDays,
         since,
         now,
         ...metadata,

src/lib/server/reports/worker.ts

@@ -1,5 +1,6 @@
 import { parentPort } from 'node:worker_threads';
 import { db } from '../db/index.js';
+import { fleetSettings } from '../settings.js';
 import { readMetrics } from '../fleet/metrics.js';
 import { getLeaderboard, getPlayerLeaderboardEntry } from '../fleet/leaderboard.js';
 import { getPlayerProfile } from '../fleet/player-profile.js';
@@ -28,6 +29,8 @@ parentPort!.on('message', ({ id, kind, input }) => {
             const key = JSON.stringify([
                 kind,
                 revision,
+                // Retention edits must be visible even without new occupancy samples.
+                kind === 'metrics' ? fleetSettings().metricsKeepDays : null,
                 timed ? Math.floor(now / 30_000) : 0,
                 timed ? input.query : input
             ]);

src/lib/ui/metrics-refresh.ts

@@ -44,6 +44,8 @@ function validReport(value: unknown): value is MetricsData {
     if (
         !record(value) ||
         ![1, 7, 30].includes(value.days as number) ||
+        !nonnegative(value.metricsKeepDays) ||
+        !Number.isInteger(value.metricsKeepDays) ||
         !numeric(value.now) ||
         !numeric(value.since) ||
         !totals(value.summary) ||

src/routes/metrics/+page.svelte

@@ -405,9 +405,11 @@
         </p>
         <p>
             Each periodic observation covers at most {ONLINE_MAX_MS / 1000} seconds. Longer collection
-            gaps are excluded. Occupancy history defaults to 31 days; saved match retention is configured
-            separately. Player-hours include all players reported by the server and are estimates, not
-            individual session records.
+            gaps are excluded. Occupancy history is retained {report.metricsKeepDays === 0
+                ? 'indefinitely'
+                : `for ${report.metricsKeepDays} ${report.metricsKeepDays === 1 ? 'day' : 'days'}`};
+            saved match retention is configured separately. Player-hours include all players
+            reported by the server and are estimates, not individual session records.
         </p>
         <p>
             Timeline buckets are aligned to UTC, with labels shown in {report.scope.timeZone.replaceAll(