Add OpenAI key save and test controls

server.js

@@ -86,6 +86,7 @@ async function adminApi(req, res, url) {
   if (url.pathname === "/api/admin/events" && req.method === "GET") return eventStream(req, res, url, "admin");
   if (url.pathname === "/api/admin/site" && req.method === "PATCH") return updateSite(req, res);
   if (url.pathname === "/api/admin/ai/models" && req.method === "GET") return adminAiModels(res);
+  if (url.pathname === "/api/admin/ai/test" && req.method === "POST") return adminAiTest(res);
   if (url.pathname === "/api/admin/conversations" && req.method === "GET") return adminConversations(res);
   if (url.pathname === "/api/admin/visitors" && req.method === "GET") return adminVisitors(res);
   if (url.pathname.match(/^\/api\/admin\/visitors\/[^/]+$/) && req.method === "PATCH") return updateVisitorProfile(req, res, url);
@@ -471,6 +472,27 @@ async function adminAiModels(res) {
   }
 }
 
+async function adminAiTest(res) {
+  const settings = getTranslationSettings();
+  const apiKey = settings.openaiApiKey;
+  if (!apiKey) return json(res, 400, { ok: false, error: "missing_openai_api_key" });
+  try {
+    const response = await fetch("https://api.openai.com/v1/models", {
+      headers: { "Authorization": `Bearer ${apiKey}` }
+    });
+    if (!response.ok) return json(res, 400, { ok: false, error: `openai_http_${response.status}` });
+    const data = await response.json();
+    return json(res, 200, {
+      ok: true,
+      key: maskApiKey(apiKey),
+      modelCount: Array.isArray(data.data) ? data.data.length : 0
+    });
+  } catch (error) {
+    console.error("openai_test_failed", error.message);
+    return json(res, 502, { ok: false, error: "openai_test_failed" });
+  }
+}
+
 async function updateConversationStatus(req, res, url) {
   const body = await readJson(req);
   const status = ["new", "open", "resolved", "spam"].includes(body.status) ? body.status : null;