docs(admin): say which providers the server-key base URL accepts

The operator card offered a free-text base URL with an OpenAI placeholder
and no word about what else it takes, so an Anthropic endpoint looked
unsupported even though the field accepts that host. One line beside the
existing hints, in all seven locales, plus the changelog entry.

CHANGELOG.md

@@ -1,5 +1,20 @@
 # Changelog
 
+## [Unreleased]
+
+### Fixed
+
+- **The AI server key reaches Anthropic when the base URL points there.** An
+  operator who filled the server key with an Anthropic key and
+  `https://api.anthropic.com/v1` got a failure on every AI call and nothing
+  saying why: the request was built for OpenAI's API and posted at Anthropic's,
+  which speaks a different shape. The base URL now picks the client. Anthropic's
+  host, and any subdomain of it, is called on Anthropic's Messages API and
+  defaults to a Claude model; every other host keeps the OpenAI-compatible API
+  it had before, which is also the right one for a local server or a gateway. A
+  base URL that is not a URL at all behaves as it did. The operator card now
+  says which providers the field accepts. Found in a fork by @sweidinger.
+
 ## [1.38.3] — 2026-09-02
 
 An account with two-factor can be deleted from the phone, and every data

messages/de.json

@@ -6473,6 +6473,7 @@
       "description": "Ein Betreiber-Schlüssel für Konten, die keinen eigenen hinterlegt haben.",
       "byokHint": "Der eigene Schlüssel (BYOK, ChatGPT-Login oder lokaler Provider) hat immer Vorrang — der Server-Schlüssel ist die letzte Stufe der Provider-Kette.",
       "consentHint": "Anfragen über den Server-Schlüssel erfordern die aktive KI-Einwilligung der Person; ohne Einwilligungsbeleg wird nichts gesendet.",
+      "baseUrlHint": "Die Basis-URL bestimmt die API: eine Anthropic-URL wie https://api.anthropic.com/v1 wird erkannt, jeder andere Host wird über die OpenAI-kompatible API angesprochen.",
       "statusConfigured": "Eingerichtet",
       "statusNotConfigured": "Nicht eingerichtet",
       "keyLabel": "API-Schlüssel",

messages/en.json

@@ -6473,6 +6473,7 @@
       "description": "An operator key for accounts that have not configured one of their own.",
       "byokHint": "A user's own key (BYOK, ChatGPT login or local provider) always takes precedence — the server key is the last step in the provider chain.",
       "consentHint": "Requests over the server key require the user's active AI consent; without a consent receipt nothing is sent.",
+      "baseUrlHint": "The base URL selects the API: an Anthropic URL such as https://api.anthropic.com/v1 is understood, any other host is called on the OpenAI-compatible API.",
       "statusConfigured": "Configured",
       "statusNotConfigured": "Not configured",
       "keyLabel": "API key",

messages/es.json

@@ -6473,6 +6473,7 @@
       "description": "Una clave del operador para las cuentas que no tienen una propia.",
       "byokHint": "La clave propia del usuario (BYOK, inicio de sesión de ChatGPT o proveedor local) siempre tiene prioridad — la clave del servidor es el último paso de la cadena de proveedores.",
       "consentHint": "Las solicitudes con la clave del servidor requieren el consentimiento de IA activo del usuario; sin un recibo de consentimiento no se envía nada.",
+      "baseUrlHint": "La URL base determina la API: se reconoce una URL de Anthropic como https://api.anthropic.com/v1, cualquier otro host se llama a través de la API compatible con OpenAI.",
       "statusConfigured": "Configurada",
       "statusNotConfigured": "Sin configurar",
       "keyLabel": "Clave de API",

messages/fr.json

@@ -6473,6 +6473,7 @@
       "description": "Une clé de l'opérateur pour les comptes qui n'en ont pas configuré une.",
       "byokHint": "La clé personnelle de l'utilisateur (BYOK, connexion ChatGPT ou fournisseur local) a toujours la priorité — la clé du serveur est la dernière étape de la chaîne de fournisseurs.",
       "consentHint": "Les requêtes via la clé du serveur nécessitent le consentement IA actif de l'utilisateur ; sans justificatif de consentement, rien n'est envoyé.",
+      "baseUrlHint": "L'URL de base détermine l'API : une URL Anthropic telle que https://api.anthropic.com/v1 est reconnue, tout autre hôte est appelé via l'API compatible OpenAI.",
       "statusConfigured": "Configurée",
       "statusNotConfigured": "Non configurée",
       "keyLabel": "Clé API",

messages/it.json

@@ -6473,6 +6473,7 @@
       "description": "Una chiave dell'operatore per gli account che non ne hanno una propria.",
       "byokHint": "La chiave personale dell'utente (BYOK, accesso ChatGPT o provider locale) ha sempre la precedenza — la chiave del server è l'ultimo passo della catena dei provider.",
       "consentHint": "Le richieste tramite la chiave del server richiedono il consenso IA attivo dell'utente; senza una ricevuta di consenso non viene inviato nulla.",
+      "baseUrlHint": "L'URL di base determina l'API: un URL Anthropic come https://api.anthropic.com/v1 viene riconosciuto, qualsiasi altro host viene chiamato tramite l'API compatibile con OpenAI.",
       "statusConfigured": "Configurata",
       "statusNotConfigured": "Non configurata",
       "keyLabel": "Chiave API",

messages/ko.json

@@ -6473,6 +6473,7 @@
       "description": "자기 키를 설정하지 않은 계정을 위한 운영자 키예요.",
       "byokHint": "사용자 본인 키(BYOK, ChatGPT 로그인, 로컬 제공자)가 항상 우선해요 — 서버 키는 제공자 체인의 마지막 단계예요.",
       "consentHint": "서버 키로 나가는 요청에는 사용자의 유효한 AI 동의가 필요해요. 동의 기록이 없으면 아무것도 전송하지 않아요.",
+      "baseUrlHint": "기본 URL이 API를 결정합니다. https://api.anthropic.com/v1 같은 Anthropic 주소는 인식되며, 그 밖의 호스트는 OpenAI 호환 API로 호출됩니다.",
       "statusConfigured": "설정됨",
       "statusNotConfigured": "설정 안 됨",
       "keyLabel": "API 키",

messages/pl.json

@@ -6473,6 +6473,7 @@
       "description": "Klucz operatora dla kont, które nie mają własnego.",
       "byokHint": "Własny klucz użytkownika (BYOK, logowanie ChatGPT lub dostawca lokalny) zawsze ma pierwszeństwo — klucz serwera jest ostatnim ogniwem łańcucha dostawców.",
       "consentHint": "Żądania przez klucz serwera wymagają aktywnej zgody użytkownika na AI; bez potwierdzenia zgody nic nie jest wysyłane.",
+      "baseUrlHint": "Adres bazowy decyduje o API: adres Anthropic taki jak https://api.anthropic.com/v1 jest rozpoznawany, każdy inny host jest wywoływany przez API zgodne z OpenAI.",
       "statusConfigured": "Skonfigurowany",
       "statusNotConfigured": "Nieskonfigurowany",
       "keyLabel": "Klucz API",

src/components/admin/ai-server-key-section.tsx

@@ -34,6 +34,10 @@ import { PasswordInput } from "./_shared";
  *     key here never silently forwards anyone's health data.
  *   - The base URL is locked server-side to HTTPS + a hostname allowlist
  *     (`ADMIN_AI_BASE_URL_ALLOWLIST` extends it).
+ *   - The base URL also picks the wire: an `anthropic.com` host is called on
+ *     Anthropic's Messages API, every other host on the OpenAI-compatible one
+ *     (`resolveAdminProvider` in `src/lib/ai/provider.ts`). `baseUrlHint` is
+ *     that sentence for the operator.
  */
 
 interface AiServerKeyResponse {
@@ -113,6 +117,7 @@ export function AiServerKeySection() {
         <div className="space-y-2 text-sm">
           <p>{t("admin.aiServerKey.byokHint")}</p>
           <p>{t("admin.aiServerKey.consentHint")}</p>
+          <p>{t("admin.aiServerKey.baseUrlHint")}</p>
         </div>
 
         <div className="space-y-1.5">