fix(firms): label a snapshot that ends at a set time with that time, not LIVE

A FIRMS source may answer the 24 hours to a set time, naming its end as
`at` (epoch ms). The layer row then reads "24 h to MM-DD HH:MM UTC"
instead of "LIVE · updated ...", and getStats() reports `at`. A
snapshot without `at` (the trailing 24 hours to now, as the dev proxy
serves) keeps the LIVE label. Translated in every catalog.

server/providers/firms.js

@@ -145,6 +145,10 @@ export async function fetchFirms(
  *
  * Routes:
  *   GET /api/firms        → {fetchedAt, stale, ttlMs, sources, count, fires}
+ *
+ * The trailing 24 hours to now. A source may instead answer the 24 hours to
+ * a set time, naming its end as `at` (epoch ms); the layer's row then shows
+ * that time rather than LIVE. This proxy never sets `at`.
  *   GET /api/firms/status → {hasKey, lastFetch, count, stale, ttlMs, transactions}
  *
  * Keyless (no FIRMS_MAP_KEY): /api/firms → 503 {error:'no_key'}; status →

src/i18n/firms-live-zh.test.mjs

@@ -43,3 +43,43 @@ for (const [age, zh, en, hant] of cases) {
     }
   });
 }
+
+test('a FIRMS snapshot that ends at a set time names it instead of LIVE', (context) => {
+  const now = 1800000000000;
+  context.mock.method(Date, 'now', () => now);
+  const previousLocale = getLocale();
+  const at = Date.UTC(2026, 9, 21, 15);
+  const layerState = {
+    _loading: false,
+    _stale: false,
+    _keyRequired: false,
+    _error: null,
+    _lastUpdate: now - 120000,
+    _at: at,
+    _count: 1,
+    _cellCount: 0,
+    _fires: [],
+  };
+  const model = createModel({ services: { anchors: {} } });
+  const { methods } = createQueries({
+    layerState,
+    components: { model },
+    config: {},
+  });
+  try {
+    setLocale('en');
+    assert.equal(methods.getStats().loadingLabel, '24 h to 10-21 15:00 UTC');
+    assert.equal(methods.getStats().at, at);
+    setLocale('de');
+    assert.equal(
+      methods.getStats().loadingLabel,
+      '24 Std. bis 21.10. 15:00 UTC',
+    );
+    layerState._at = null;
+    setLocale('en');
+    assert.equal(methods.getStats().loadingLabel, 'LIVE · updated 2m ago');
+    assert.equal(methods.getStats().at, null);
+  } finally {
+    setLocale(previousLocale);
+  }
+});

src/i18n/locales/ar.json

@@ -879,6 +879,7 @@
   "KEY REQUIRED": "المفتاح مطلوب",
   "STALE · cached {age}": "متقادم · مخزّن {age}",
   "LIVE · updated {age}": "مباشر · حُدّث {age}",
+  "24 h to {day} {time} UTC": "24 ساعة حتى {day} {time} UTC",
   "<1m ago": "قبل أقل من دقيقة",
   "FIRE · {frp} MW": "حريق · {frp} MW",
   "▲ {frp} MW": "▲ {frp} MW",

src/i18n/locales/de.json

@@ -164,6 +164,7 @@
   "loading...": "lädt...",
   "KEY REQUIRED": "SCHLÜSSEL ERFORDERLICH",
   "LIVE · updated {age}": "LIVE · aktualisiert {age}",
+  "24 h to {day} {time} UTC": "24 Std. bis {day} {time} UTC",
   "loading mapped installation context": "Kontext der kartierten Anlage wird geladen",
   "MAPPED INSTALLATION": "KARTIERTE ANLAGE",
   "LAUNCH SITE · {site}": "STARTPLATZ · {site}",

src/i18n/locales/es.json

@@ -737,6 +737,7 @@
   "KEY REQUIRED": "CLAVE REQUERIDA",
   "STALE · cached {age}": "DESACTUALIZADO · en caché hace {age}",
   "LIVE · updated {age}": "EN VIVO · actualizado {age}",
+  "24 h to {day} {time} UTC": "24 h hasta {day} {time} UTC",
   "<1m ago": "hace <1 min",
   "FIRE · {frp} MW": "INCENDIO · {frp} MW",
   "▲ {frp} MW": "▲ {frp} MW",

src/i18n/locales/fr.json

@@ -734,6 +734,7 @@
   "loading...": "chargement…",
   "KEY REQUIRED": "CLÉ REQUISE",
   "LIVE · updated {age}": "DIRECT · mis à jour {age}",
+  "24 h to {day} {time} UTC": "24 h jusqu’au {day} {time} UTC",
   "Source snapshot time unavailable": "Heure de l'instantané source indisponible",
   "Live data unavailable": "Données en direct indisponibles",
   "Intel Picture": "Situation renseignement",

src/i18n/locales/it.json

@@ -734,6 +734,7 @@
   "loading...": "caricamento...",
   "KEY REQUIRED": "CHIAVE RICHIESTA",
   "LIVE · updated {age}": "LIVE · aggiornato {age}",
+  "24 h to {day} {time} UTC": "24 h fino al {day} {time} UTC",
   "Source snapshot time unavailable": "Ora dello snapshot della fonte non disponibile",
   "Live data unavailable": "Dati live non disponibili",
   "Intel Picture": "Quadro intelligence",

src/i18n/locales/ja.json

@@ -716,6 +716,7 @@
   "loading...": "読込中…",
   "KEY REQUIRED": "キーが必要",
   "LIVE · updated {age}": "ライブ · 更新 {age}",
+  "24 h to {day} {time} UTC": "{day} {time} UTC までの24時間",
   "Source snapshot time unavailable": "ソースのスナップショット時刻を取得できません",
   "Live data unavailable": "ライブデータを利用できません",
   "Intel Picture": "情勢図",

src/i18n/locales/pt.json

@@ -732,6 +732,7 @@
   "loading...": "carregando...",
   "KEY REQUIRED": "CHAVE NECESSÁRIA",
   "LIVE · updated {age}": "AO VIVO · atualizado {age}",
+  "24 h to {day} {time} UTC": "24 h até {day} {time} UTC",
   "Source snapshot time unavailable": "Horário do snapshot da fonte indisponível",
   "Live data unavailable": "Dados ao vivo indisponíveis",
   "Intel Picture": "Panorama de inteligência",

src/i18n/locales/ru.json

@@ -147,6 +147,7 @@
   "loading...": "загрузка...",
   "KEY REQUIRED": "ТРЕБУЕТСЯ КЛЮЧ",
   "LIVE · updated {age}": "ОНЛАЙН · обновлено {age}",
+  "24 h to {day} {time} UTC": "24 ч до {day} {time} UTC",
   "Retrying mapped sites…": "Повторный запрос объектов…",
   "Fetching mapped sites…": "Загрузка объектов…",
   "Zoom in to search mapped installations": "Приблизьте, чтобы искать картографированные объекты",

src/i18n/locales/uk.json

@@ -742,6 +742,7 @@
   "loading...": "завантаження...",
   "KEY REQUIRED": "ПОТРІБЕН КЛЮЧ",
   "LIVE · updated {age}": "ОНЛАЙН · оновлено {age}",
+  "24 h to {day} {time} UTC": "24 год до {day} {time} UTC",
   "Source snapshot time unavailable": "Час знімка джерела невідомий",
   "Live data unavailable": "Дані в реальному часі недоступні",
   "Intel Picture": "Розвідувальна обстановка",

src/i18n/locales/zh-CN.json

@@ -716,6 +716,7 @@
   "loading...": "加载中…",
   "KEY REQUIRED": "需要密钥",
   "LIVE · updated {age}": "实时 · 更新于 {age}",
+  "24 h to {day} {time} UTC": "截至 {day} {time} UTC 的 24 小时",
   "Source snapshot time unavailable": "来源快照时间不可用",
   "Live data unavailable": "实时数据不可用",
   "Low-accuracy score < 2%": "低精度评分 < 2%",

src/i18n/locales/zh-Hant.json

@@ -711,6 +711,7 @@
   "loading...": "加載中…",
   "KEY REQUIRED": "需要密鑰",
   "LIVE · updated {age}": "實時 · 更新於 {age}",
+  "24 h to {day} {time} UTC": "截至 {day} {time} UTC 的 24 小時",
   "Source snapshot time unavailable": "來源快照時間不可用",
   "Live data unavailable": "實時數據不可用",
   "Low-accuracy score < 2%": "低精度評分 < 2%",

src/layers/firms/ingestion.js

@@ -39,6 +39,9 @@ export function createIngestion({
       layerState._keyRequired = false;
       layerState._error = null;
       layerState._stale = Boolean(payload?.stale);
+      // A snapshot of the 24 hours to a set time names it; one of the
+      // trailing 24 hours to now does not.
+      layerState._at = Number.isFinite(payload?.at) ? payload.at : null;
       const previousSelection = layerState._selectedFire;
       layerState._selectedFire = null;
       layerState._allFires = adaptFirmsRecords(payload?.fires);

src/layers/firms/lifecycle.js

@@ -127,6 +127,7 @@ export function createLifecycle({
       layerState._rowControlsListener = null;
       layerState._cellCount = 0;
       layerState._lastUpdate = null;
+      layerState._at = null;
       layerState._keyRequired = false;
       layerState._stale = false;
       layerState._error = null;

src/layers/firms/queries.js

@@ -8,7 +8,7 @@ import {
   rampTrackGradient,
   sliderPositionForFrp,
 } from '../../data/firmsIntensity.js';
-import { formatNumber, t } from '../../i18n/index.js';
+import { formatNumber, formatUtcDayMonth, t } from '../../i18n/index.js';
 import { LOD_LEVELS, REFRESH_INTERVAL_MS } from './policy.js';
 
 /** Slider resolution: whole-percent positions along the log axis. */
@@ -190,8 +190,9 @@ export function createQueries({
      * Layer stats for the data panel. Degraded feed states surface through
      * `error` (established qa-failstate pattern: a dead feed must never look
      * like a healthy empty layer) with a matching human `loadingLabel`:
-     * 'LIVE · updated Xm ago' fresh, 'STALE · cached Xh' when the proxy
-     * served past-TTL cache, 'KEY REQUIRED' keyless.
+     * 'LIVE · updated Xm ago' fresh, '24 h to MM-DD HH:MM UTC' for a
+     * snapshot that ends at a set time (`at`), 'STALE · cached Xh' when the
+     * proxy served past-TTL cache, 'KEY REQUIRED' keyless.
      */
     getStats() {
       const now = Date.now();
@@ -213,6 +214,11 @@ export function createQueries({
         loadingLabel = staleText;
       } else if (layerState._error) {
         loadingLabel = layerState._error;
+      } else if (Number.isFinite(layerState._at)) {
+        loadingLabel = t('24 h to {day} {time} UTC', {
+          day: formatUtcDayMonth(layerState._at),
+          time: new Date(layerState._at).toISOString().slice(11, 16),
+        });
       } else if (layerState._lastUpdate) {
         loadingLabel = t('LIVE · updated {age}', {
           age: components.model.formatAgoMinutes(now - layerState._lastUpdate),
@@ -226,6 +232,9 @@ export function createQueries({
         lastUpdate: layerState._lastUpdate,
         loading: layerState._loading,
         stale: layerState._stale,
+        // The end of the 24 hours shown when the snapshot ends at a set time;
+        // null for the trailing 24 hours to now.
+        at: Number.isFinite(layerState._at) ? layerState._at : null,
         // The machine-readable half of the keyless state, ahead of the human
         // strings below: without it "no key configured" is indistinguishable
         // from a broken feed, and the row reads as a fault instead of a step

src/layers/firms/state.js

@@ -77,6 +77,8 @@ export function createFirmsState({ services, config }) {
 
   layerState._lastUpdate = null;
 
+  layerState._at = null;
+
   layerState._currentLodId = null;
 
   layerState._currentLodIndex = -1;