Build fixes: offline-safe fonts, Next.js API route type updates, TS strict errors resolved, MUI import cleanup, chat markdown wrapper, Azure OpenAI typing, caching key + chapter API id types, and misc error-logging typings.

components/chat/chat-interface.tsx

@@ -84,9 +84,11 @@ export function ChatInterface() {
               }`}
             >
               {msg.role === 'assistant' ? (
-                <ReactMarkdown className="prose prose-sm max-w-none">
-                  {msg.content}
-                </ReactMarkdown>
+                <div className="prose prose-sm max-w-none">
+                  <ReactMarkdown>
+                    {msg.content}
+                  </ReactMarkdown>
+                </div>
               ) : (
                 <p>{msg.content}</p>
               )}
@@ -129,4 +131,4 @@ export function ChatInterface() {
       </form>
     </div>
   )
-}
+}