Add agent selection and artifact management to RowboatX UI

- Implemented agent selection dropdown in the input area.
- Enhanced artifact management with loading, saving, and error handling.
- Added new API routes for fetching agent summaries and run details.
- Updated sidebar to display agents, configurations, and runs dynamically.
- Introduced theme selection options in the user navigation menu.

apps/rowboatx/app/api/chat/route.ts

@@ -11,7 +11,7 @@ export const dynamic = 'force-dynamic';
 export async function POST(request: NextRequest) {
   try {
     const body = await request.json();
-    const { message, runId } = body;
+    const { message, runId, agentId } = body;
 
     if (!message || typeof message !== 'string') {
       return Response.json(
@@ -25,7 +25,7 @@ export async function POST(request: NextRequest) {
     // Create new run if no runId provided
     if (!currentRunId) {
       const run = await cliClient.createRun({
-        agentId: 'copilot',
+        agentId: agentId || 'copilot',
       });
       currentRunId = run.id;
     }