Remove a key I authored and never used

sheet.isoLine turned check:i18n-never-translated red: "· ISO 639-3" is identical
in all eleven locales, because a standard's designation correctly is.

The suggested fix was an ALLOWED entry, but the key has ZERO call sites — I
authored it during the label batch and never wired it. An exemption would have
made the gate quiet about a string nothing renders, which is worse than the red:
it spends the exemption list's credibility on a key that should not exist.

The line it was meant for (charts.vue:577) keeps "· ISO 639-3" as plain text, and
check:hardcoded-english does not flag it — correctly, since a standard's name is
not prose. So there was never anything to translate here.

Removed from all eleven. never-translated PASSES, parity and keys-exist unchanged.

library/i18n/locales/ar/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} نسمة",
     "hasResources": "ذات صلة: {lang} لديها موارد",
     "loadingTable": "جارٍ تحميل {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} نسمة · {countries}"
   },
   "res": {

library/i18n/locales/de/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} Menschen",
     "hasResources": "verwandt: {lang} hat Ressourcen",
     "loadingTable": "{table} wird geladen…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} Menschen · {countries}"
   },
   "res": {

library/i18n/locales/en/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} people",
     "hasResources": "related: {lang} has resources",
     "loadingTable": "Loading {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} people · {countries}"
   },
   "res": {

library/i18n/locales/es/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} personas",
     "hasResources": "relacionada: {lang} tiene recursos",
     "loadingTable": "Cargando {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} personas · {countries}"
   },
   "res": {

library/i18n/locales/fr/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} personnes",
     "hasResources": "apparentée : {lang} a des ressources",
     "loadingTable": "Chargement de {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} personnes · {countries}"
   },
   "res": {

library/i18n/locales/hi/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} लोग",
     "hasResources": "संबंधित: {lang} के पास संसाधन हैं",
     "loadingTable": "{table} लोड हो रहा है…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} लोग · {countries}"
   },
   "res": {

library/i18n/locales/it/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} persone",
     "hasResources": "correlata: {lang} ha risorse",
     "loadingTable": "Caricamento di {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} persone · {countries}"
   },
   "res": {

library/i18n/locales/pt/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} pessoas",
     "hasResources": "relacionada: {lang} tem recursos",
     "loadingTable": "Carregando {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} pessoas · {countries}"
   },
   "res": {

library/i18n/locales/ro/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} persoane",
     "hasResources": "înrudită: {lang} are resurse",
     "loadingTable": "Se încarcă {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} persoane · {countries}"
   },
   "res": {

library/i18n/locales/ru/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} человек",
     "hasResources": "родственный: {lang} имеет ресурсы",
     "loadingTable": "Загрузка {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} человек · {countries}"
   },
   "res": {

library/i18n/locales/zh/gospel.json

@@ -88,7 +88,6 @@
     "popSuffix": "· {pop} 人",
     "hasResources": "相关：{lang} 有资源",
     "loadingTable": "正在加载 {table}…",
-    "isoLine": "· ISO 639-3",
     "popCountries": "{pop} 人 · {countries}"
   },
   "res": {