refactor: address code review feedback — remove redundant type check, extract output formatter

Agent-Logs-Url: https://github.com/objectstack-ai/framework/sessions/8a978a0a-5a20-45f0-b841-51f0a8857945

Co-authored-by: xuyushun441-sys <255036401+xuyushun441-sys@users.noreply.github.com>

Author: Copilot

apps/studio/src/components/AiChatPanel.tsx

@@ -48,7 +48,7 @@ function formatToolArgs(input: unknown): string {
     .slice(0, 4)
     .map(([k, v]) => {
       const val = typeof v === 'string' ? v : JSON.stringify(v);
-      const display = typeof val === 'string' && val.length > 30 ? val.slice(0, 30) + '…' : val;
+      const display = val.length > 30 ? val.slice(0, 30) + '…' : val;
       return `${k}: ${display}`;
     })
     .join(', ');
@@ -61,6 +61,14 @@ function isToolPart(part: UIMessage['parts'][number]): part is Extract<UIMessage
   return part.type === 'dynamic-tool';
 }
 
+/**
+ * Format tool output for display, truncating to a max length.
+ */
+function formatToolOutput(output: unknown, maxLen = 80): string {
+  const raw = typeof output === 'string' ? output : JSON.stringify(output);
+  return raw.length > maxLen ? raw.slice(0, maxLen) + '…' : raw;
+}
+
 // ── Tool Invocation State Labels ────────────────────────────────────
 
 interface ToolInvocationDisplayProps {
@@ -144,9 +152,7 @@ function ToolInvocationDisplay({ part, onApprove, onDeny }: ToolInvocationDispla
           <div className="min-w-0">
             <span className="font-medium">{toolLabel}</span>
             <p className="mt-0.5 text-muted-foreground truncate">
-              {typeof part.output === 'string'
-                ? part.output.length > 80 ? part.output.slice(0, 80) + '…' : part.output
-                : JSON.stringify(part.output).slice(0, 80)}
+              {formatToolOutput(part.output)}
             </p>
           </div>
         </div>