fix(shell): stale tabs now know the gateway was updated

Recurring confusion all day: the SPA lives in an open tab until reload, so
after a gateway rebuild/update users kept seeing (and benchmarking with!) an
old interface — "where is the feature", "why are the test ids old". The meta
endpoint now carries the process start timestamp; the existing 20s health
poll compares it, and when the gateway has restarted the tab shows a fixed
banner: "The gateway was updated — this page is running an older interface"
with a one-click Reload. 2 strings in all 7 languages.

web/js/i18n/de.js

@@ -619,4 +619,6 @@ export default {
   "bm.degraded": "Router degradiert",
   "bm.routerDegraded": "Der Router hat nicht rechtzeitig geantwortet — die Anfrage nutzte die Fallback-Kette; die Klassifikation wird nicht gewertet.",
   "bm.cutByCap": "Budget ging fürs Denken drauf — keine Antwort mehr",
+  "shell.uiStale": "Das Gateway wurde aktualisiert — diese Seite zeigt eine ältere Oberfläche.",
+  "shell.reload": "Neu laden",
 };

web/js/i18n/en.js

@@ -612,4 +612,6 @@ export default {
   "bm.degraded": "router degraded",
   "bm.routerDegraded": "The router did not answer in time — the request used the fallback chain; classification is not judged.",
   "bm.cutByCap": "budget spent on reasoning — answer never came",
+  "shell.uiStale": "The gateway was updated — this page is running an older interface.",
+  "shell.reload": "Reload",
 };

web/js/i18n/es.js

@@ -619,4 +619,6 @@ export default {
   "bm.degraded": "router degradado",
   "bm.routerDegraded": "El router no respondió a tiempo — la petición usó la cadena de reserva; la clasificación no se cuenta.",
   "bm.cutByCap": "presupuesto gastado en razonar — sin respuesta final",
+  "shell.uiStale": "La pasarela se actualizó — esta página usa una interfaz antigua.",
+  "shell.reload": "Recargar",
 };

web/js/i18n/fr.js

@@ -619,4 +619,6 @@ export default {
   "bm.degraded": "routeur dégradé",
   "bm.routerDegraded": "Le routeur n'a pas répondu à temps — la requête a suivi la chaîne de secours ; la classification n'est pas comptée.",
   "bm.cutByCap": "budget épuisé en raisonnement — pas de réponse",
+  "shell.uiStale": "La passerelle a été mise à jour — cette page utilise une ancienne interface.",
+  "shell.reload": "Recharger",
 };

web/js/i18n/ru.js

@@ -611,4 +611,6 @@ export default {
   "bm.degraded": "роутер деградировал",
   "bm.routerDegraded": "Роутер не успел ответить — запрос ушёл по резервной цепочке; классификация не засчитывается.",
   "bm.cutByCap": "бюджет ушёл на размышления — ответ не успел",
+  "shell.uiStale": "Шлюз обновился — на этой странице старый интерфейс.",
+  "shell.reload": "Перезагрузить",
 };

web/js/i18n/tr.js

@@ -619,4 +619,6 @@ export default {
   "bm.degraded": "yönlendirici yedeğe düştü",
   "bm.routerDegraded": "Yönlendirici zamanında yanıt vermedi — istek yedek zincire gitti; sınıflandırma sayılmaz.",
   "bm.cutByCap": "bütçe düşünmeye gitti — yanıt gelemedi",
+  "shell.uiStale": "Ağ geçidi güncellendi — bu sayfa eski arayüzü çalıştırıyor.",
+  "shell.reload": "Yeniden yükle",
 };

web/js/i18n/zh.js

@@ -619,4 +619,6 @@ export default {
   "bm.degraded": "路由器降级",
   "bm.routerDegraded": "路由器未及时响应 — 请求走了备用链路；分类不计入统计。",
   "bm.cutByCap": "预算全用于思考——未能给出答案",
+  "shell.uiStale": "网关已更新 — 此页面运行的是旧界面。",
+  "shell.reload": "重新加载",
 };