Remove truncation from timeline chart event details

Previously, agent responses in the event details box were truncated
to 1000 characters with a "[Truncated]" message. This change removes
the truncation logic to show all lines of the agent response.

🤖 Generated with Codebuff
Co-Authored-By: Codebuff <noreply@codebuff.com>

Author: brandonkachen

web/src/app/admin/traces/components/timeline-chart.tsx

@@ -572,10 +572,7 @@ export function TimelineChart({
                             </h4>
                             <div className="bg-muted p-3 rounded overflow-auto max-h-96">
                               <pre className="text-xs whitespace-pre-wrap">
-                                {responseContent.length > 1000
-                                  ? responseContent.substring(0, 1000) +
-                                    '...\n\n[Truncated - showing first 1000 characters]'
-                                  : responseContent}
+                                {responseContent}
                               </pre>
                             </div>
                           </div>