fix(web): harden typed SPA chat lifecycle

Co-Authored-By: Claude Haiku 4.5 <[email protected]>

apps/web/src/spa/chat/tool-call-list.tsx

@@ -6,9 +6,17 @@ export function ToolCallList({ tools }: { tools: ToolCallState[] }): ReactElemen
 
   return (
     <ul aria-label="Tool calls" className="flex flex-col gap-1 px-4 pb-2 text-xs">
-      {tools.map((tool) => (
-        <li key={tool.toolCallId} role={tool.status === 'error' ? 'alert' : 'status'}>
-          {tool.toolName} — {tool.status}
+      {tools.map((tool, index) => (
+        <li
+          // A valid server-controlled toolCallId can legitimately repeat
+          // (e.g. two tool:start events sharing one id) — keying on it alone
+          // would give React two identical keys. Pairing it with its
+          // (stable, append-only) render index keeps every key unique.
+          key={`${tool.toolCallId}-${index}`}
+          role={tool.status === 'error' || tool.status === 'anomaly' ? 'alert' : 'status'}
+        >
+          {tool.toolName} —{' '}
+          {tool.status === 'anomaly' ? 'unexpected end (unknown tool call)' : tool.status}
         </li>
       ))}
     </ul>