diff --git a/apps/web/src/components/chat/MessagesTimeline.logic.test.ts b/apps/web/src/components/chat/MessagesTimeline.logic.test.ts
index 6d74204bc1cae3c94aeeae8afbe8b7187191318e..70a330d4630340f2a5ea8df3893b005e68bf454d 100644
--- a/apps/web/src/components/chat/MessagesTimeline.logic.test.ts
+++ b/apps/web/src/components/chat/MessagesTimeline.logic.test.ts
@@ -5,8 +5,20 @@ import {
   deriveMessagesTimelineRows,
   normalizeCompactToolLabel,
   resolveAssistantMessageCopyState,
+  shouldPreserveAssistantLineBreaks,
 } from "./MessagesTimeline.logic";
 
+describe("shouldPreserveAssistantLineBreaks", () => {
+  it("preserves Claude insight formatting without changing regular markdown", () => {
+    expect(
+      shouldPreserveAssistantLineBreaks(
+        "★ Insight ─────────────────\\nFirst observation\\nSecond observation\\n─────────────────",
+      ),
+    ).toBe(true);
+    expect(shouldPreserveAssistantLineBreaks("A normal\\nmarkdown paragraph")).toBe(false);
+  });
+});
+
 describe("computeMessageDurationStart", () => {
   it("returns message createdAt when there is no preceding user message", () => {
     const result = computeMessageDurationStart([
diff --git a/apps/web/src/components/chat/MessagesTimeline.logic.ts b/apps/web/src/components/chat/MessagesTimeline.logic.ts
index 6bc0a2a6203c355149d22ede43223f64a90bb5f9..c89bbd0557d9eaf924df977a95cc4d593e3d3228 100644
--- a/apps/web/src/components/chat/MessagesTimeline.logic.ts
+++ b/apps/web/src/components/chat/MessagesTimeline.logic.ts
@@ -52,6 +52,10 @@ export function resolveTimelineIsAtEnd(
   return contentLength - scroll - scrollLength - endInset <= TIMELINE_FOLLOW_REARM_THRESHOLD_PX;
 }
 
+export function shouldPreserveAssistantLineBreaks(text: string): boolean {
+  return /^★ Insight(?:\s|─)/mu.test(text);
+}
+
 export function resolveTimelineMinimapHeightStyle(itemCount: number): string {
   const naturalHeight = Math.max(1, (itemCount - 1) * TIMELINE_MINIMAP_ITEM_SPACING);
   return `min(${naturalHeight}px, ${TIMELINE_MINIMAP_MAX_HEIGHT_CSS})`;
diff --git a/apps/web/src/components/chat/MessagesTimeline.tsx b/apps/web/src/components/chat/MessagesTimeline.tsx
index f9ad57ff3b83daef28abde4504a77c82d5b75797..f5c529ff315f33f6e54e49430638f3ae4eda30eb 100644
--- a/apps/web/src/components/chat/MessagesTimeline.tsx
+++ b/apps/web/src/components/chat/MessagesTimeline.tsx
@@ -83,6 +83,7 @@ import {
   resolveTimelineMinimapIndexFromPointer,
   resolveTimelineMinimapInteractiveWidth,
   resolveTimelineMinimapTopPercent,
+  shouldPreserveAssistantLineBreaks,
   type StableMessagesTimelineRowsState,
   type MessagesTimelineRow,
   TIMELINE_MINIMAP_MIN_ITEMS,
@@ -1113,6 +1114,7 @@ function AssistantTimelineRow({ row }: { row: Extract<TimelineRow, { kind: "mess
           cwd={ctx.markdownCwd}
           threadRef={ctx.threadRef ?? undefined}
           isStreaming={Boolean(row.message.streaming)}
+          lineBreaks={shouldPreserveAssistantLineBreaks(messageText)}
           skills={ctx.skills}
         />
         <AssistantChangedFilesSection