feat: complete tRPC integration and fix platform UI issues

- Implement comprehensive tRPC setup with type-safe API
- Create tRPC routers for dashboard, admin, and auth endpoints
- Migrate frontend components to use tRPC client
- Fix platform dashboard Settings button functionality
- Add platform settings page with profile and security management
- Create OpenAI API mocking infrastructure for cost-safe testing
- Update tests to work with new tRPC architecture
- Sync database schema to fix AIBatchRequest table errors

components/MessageViewer.tsx

@@ -71,8 +71,7 @@ export default function MessageViewer({ messages }: MessageViewerProps) {
               : "No timestamp"}
           </span>
           <span>
-            Last message:{" "}
-            {(() => {
+            Last message: {(() => {
               const lastMessage = messages[messages.length - 1];
               return lastMessage.timestamp
                 ? new Date(lastMessage.timestamp).toLocaleString()