fix(studio): keep AI provider and model details private

app/lib/studio-ai.ts

@@ -18,23 +18,21 @@ type FailureKind =
   | "response"
   | "request";
 const failureMessages: Record<FailureKind, string> = {
-  auth: "APIMart rejected the server API key. Check APIMART_API_KEY and its permissions, then restart the app.",
+  auth: "AI generation is unavailable due to a server configuration issue. Contact the site administrator.",
   quota:
-    "APIMart reports insufficient credit or quota. Check the provider account balance and limits.",
+    "AI generation has reached its service usage limit. Try again later or contact the site administrator.",
   model:
-    "APIMart could not access the configured model. Check that this model is enabled for the server API key.",
-  rate: "APIMart is rate limiting requests. Wait a minute and generate again.",
-  unavailable:
-    "APIMart is temporarily unavailable. Try generating again shortly.",
-  network:
-    "The server could not reach APIMart. Check the VM's outbound HTTPS connection and try again.",
+    "AI generation is unavailable due to a server configuration issue. Contact the site administrator.",
+  rate: "AI generation is rate limiting requests. Wait a minute and generate again.",
+  unavailable: "AI generation is temporarily unavailable. Try again shortly.",
+  network: "The server could not reach the AI service. Try again shortly.",
   truncated:
-    "APIMart stopped before completing all design alternatives. Try a shorter brief or generate again.",
-  filtered: "APIMart declined this generation. Revise the brief and try again.",
-  response:
-    "APIMart returned an empty or unreadable completion. Try generating again.",
+    "AI generation stopped before completing all design alternatives. Try a shorter brief or generate again.",
+  filtered:
+    "This generation could not be completed. Revise the brief and try again.",
+  response: "AI generation returned an empty or unreadable result. Try again.",
   request:
-    "APIMart rejected the completion request. Check the provider's model configuration.",
+    "AI generation could not process this request. Try again or contact the site administrator.",
 };
 class APIMartFailure extends Error {
   constructor(
@@ -202,8 +200,7 @@ function synchronousStudioAI(
       return json({ error: "Same-origin requests only." }, 403);
     if (url.pathname.endsWith("/generation") && request.method === "GET")
       return json({
-        provider: "APIMart",
-        model,
+        provider: "AI",
         templateVersion: 1,
         delivery: "polling",
         maxAttempts: 2,
@@ -291,7 +288,7 @@ function synchronousStudioAI(
             code: "WRN-STUDIO-PROPOSAL",
             path: "$",
             message:
-              "APIMart returned a design that did not meet the schema after both provider requests were used. Generate again. Your draft and previous alternatives are unchanged.",
+              "AI generation returned a design that did not meet the schema after both attempts were used. Generate again. Your draft and previous alternatives are unchanged.",
           },
         ];
       }
@@ -317,6 +314,9 @@ function synchronousStudioAI(
           },
         ];
       }
+      // Public responses retain useful provenance without exposing infrastructure choices.
+      result.provenance.provider = "AI";
+      delete result.provenance.model;
       return json(result);
     } catch (error) {
       const message =