fix(frontend): update TimelineToolGroup to visually propagate error status with red color and X icon

vibn-frontend/components/vibn-chat/chat-panel.tsx

@@ -65,7 +65,12 @@ interface Message {
 
 type TimelineEntry =
   | { kind: "thought"; text: string }
-  | { kind: "tool"; name: string; status: "running" | "done"; result?: string }
+  | {
+      kind: "tool";
+      name: string;
+      status: "running" | "done" | "error";
+      result?: string;
+    }
   // A text segment from one round of the assistant's tool loop.
   // Each text SSE event from the server starts a new entry; subsequent
   // streaming chunks for that same round append to the most-recent
@@ -589,6 +594,7 @@ function TimelineToolGroup({
   const [expanded, setExpanded] = useState(false);
   const count = entries.length;
   const allDone = entries.every((e) => e.status === "done");
+  const hasError = entries.some((e) => e.status === "error");
 
   return (
     <div
@@ -616,7 +622,9 @@ function TimelineToolGroup({
         }}
       >
         <span style={{ width: 14, display: "flex", justifyContent: "center" }}>
-          {!allDone ? (
+          {hasError ? (
+            <span style={{ color: "#ef4444", fontWeight: "bold" }}>✗</span>
+          ) : !allDone ? (
             <Loader2
               style={{ width: 12, height: 12 }}
               className="animate-spin"
@@ -625,8 +633,9 @@ function TimelineToolGroup({
             <Wrench style={{ width: 12, height: 12, color: "#2e7d32" }} />
           )}
         </span>
-        <span style={{ flex: 1 }}>
-          {category} {count > 1 ? `(x${count})` : ""} {!allDone ? "..." : " ✓"}
+        <span style={{ flex: 1, color: hasError ? "#ef4444" : undefined }}>
+          {category} {count > 1 ? `(x${count})` : ""}
+          {hasError ? " ✗" : !allDone ? "..." : " ✓"}
         </span>
         <span
           style={{
@@ -1294,6 +1303,14 @@ export function ChatPanel({
                   // earlier same-named entries.
                   let updated = false;
                   const newTl: TimelineEntry[] = [];
+
+                  const isToolErr =
+                    typeof ev.result === "string" &&
+                    (ev.result.toLowerCase().includes("error") ||
+                      ev.result.toLowerCase().includes("failed") ||
+                      ev.result.toLowerCase().includes("unexpected") ||
+                      ev.result.toLowerCase().includes("not found"));
+
                   for (let i = tl.length - 1; i >= 0; i--) {
                     const e = tl[i];
                     if (
@@ -1304,7 +1321,7 @@ export function ChatPanel({
                     ) {
                       newTl.unshift({
                         ...e,
-                        status: "done",
+                        status: isToolErr ? "error" : "done",
                         result: ev.result,
                       });
                       updated = true;