对话：挂上聊天大纲，并修好新建对话的循环引用

src/lib/api/chat.test.ts

@@ -63,6 +63,17 @@ describe('chat API (browser mock)', () => {
     await rejected;
   });
 
+  it('createConversation drops a cyclic click-event cwd instead of throwing', async () => {
+    const cyclic: { target?: unknown } = {};
+    cyclic.target = cyclic;
+    expect(() => JSON.stringify(cyclic)).toThrow(/circular|cyclic/i);
+    const createP = createConversation(['claude'], cyclic as unknown as string);
+    await vi.runAllTimersAsync();
+    const created = await createP;
+    expect(created.agentIds).toEqual(['claude']);
+    expect(created.cwd).toBeNull();
+  });
+
   it('ensureDefaultConversation reuses the initial blank conversation', async () => {
     const firstP = ensureDefaultConversation(['claude']);
     await vi.runAllTimersAsync();

src/lib/api/chat.ts

@@ -2,6 +2,7 @@
  * Chat API façade — delegates to app runtime backend.
  */
 import { getBackend } from '@/app/runtime';
+import { createConversationCwd } from '@/lib/open-chat-cwd';
 import type { AgentKey, ChatEvent, ChatHistoryTurn, ChatMessage, Conversation } from '@/lib/types';
 import type { MarkdownFilePreviewDto } from '@/lib/backend/contracts/chat-port';
 import type { RuntimeOptions, RuntimeReply, RuntimeSnapshot, RuntimeStartExtras, RuntimeTurnSettings } from '@/lib/backend/contracts/chat-runtime';
@@ -23,7 +24,7 @@ export async function createConversation(
   agentIds: AgentKey[],
   cwd?: string | null,
 ): Promise<Conversation> {
-  return getBackend().chat.createConversation(agentIds, cwd);
+  return getBackend().chat.createConversation(agentIds, createConversationCwd(cwd));
 }
 
 export async function ensureDefaultConversation(

src/lib/backend/tauri/chat.ts

@@ -1,4 +1,5 @@
 import type { ChatPort, MarkdownFilePreviewDto } from '@/lib/backend/contracts';
+import { createConversationCwd } from '@/lib/open-chat-cwd';
 import {
   mapChatMessage,
   mapConversation,
@@ -20,7 +21,7 @@ export function createTauriChatPort(): ChatPort {
     async createConversation(agentIds, cwd) {
       const row = await invoke<CoreConversation>('create_conversation', {
         agentIds,
-        cwd: cwd ?? null,
+        cwd: createConversationCwd(cwd),
       });
       return mapConversation(row);
     },

src/lib/open-chat-cwd.test.ts

@@ -4,7 +4,9 @@ import { fileURLToPath } from 'node:url';
 import { describe, expect, it, vi } from 'vitest';
 import {
   consumePendingOpenChatCwd,
+  createConversationCwd,
   folderNameFromCwd,
+  newChatCwdArg,
   shellOpenChatBootstrap,
   shellOpenChatHref,
 } from './open-chat-cwd';
@@ -26,6 +28,25 @@ describe('folderNameFromCwd', () => {
   });
 });
 
+describe('newChatCwdArg', () => {
+  it('keeps a folder path or explicit null and drops click events', () => {
+    expect(newChatCwdArg('/workspace')).toBe('/workspace');
+    expect(newChatCwdArg(null)).toBeNull();
+    expect(newChatCwdArg(undefined)).toBeUndefined();
+    const cyclic: { target?: unknown } = {};
+    cyclic.target = cyclic;
+    expect(() => JSON.stringify(cyclic)).toThrow(/circular|cyclic/i);
+    expect(newChatCwdArg(cyclic)).toBeUndefined();
+    expect(() => JSON.stringify({
+      agentIds: ['grok'],
+      cwd: createConversationCwd(cyclic),
+    })).not.toThrow();
+    expect(createConversationCwd(cyclic)).toBeNull();
+    expect(createConversationCwd('/workspace')).toBe('/workspace');
+    expect(createConversationCwd(null)).toBeNull();
+  });
+});
+
 describe('consumePendingOpenChatCwd', () => {
   it('is a no-op when takePending returns nothing', async () => {
     const applyBootstrap = vi.fn();
@@ -85,4 +106,13 @@ describe('App open-chat wiring', () => {
       /HashRouter `useNavigate` changes identity with pathname; do not resubscribe\.\s*\n\s*\}, \[\]\);/,
     );
   });
+
+  it('omits non-string cwd before create-conversation persist and IPC', () => {
+    const dir = path.dirname(fileURLToPath(import.meta.url));
+    const api = readFileSync(path.resolve(dir, 'api/chat.ts'), 'utf8');
+    const tauri = readFileSync(path.resolve(dir, 'backend/tauri/chat.ts'), 'utf8');
+    expect(api).toContain('createConversationCwd');
+    expect(tauri).toContain('createConversationCwd');
+    expect(tauri).toContain('cwd: createConversationCwd(cwd)');
+  });
 });

src/lib/open-chat-cwd.ts

@@ -1,5 +1,21 @@
 import type { ChatBootstrap } from '@/lib/types';
 
+/**
+ * New-chat cwd for persist / IPC. Only a folder path or explicit null.
+ * Click events and other objects are dropped so JSON.stringify never sees a cycle.
+ */
+export function newChatCwdArg(value: unknown): string | null | undefined {
+  if (value === undefined) return undefined;
+  if (value === null) return null;
+  if (typeof value === 'string') return value;
+  return undefined;
+}
+
+/** Wire / invoke shape: never pass a non-string through JSON.stringify. */
+export function createConversationCwd(value: unknown): string | null {
+  return typeof value === 'string' ? value : null;
+}
+
 /** Last path segment for a folder chosen in the OS file manager. */
 export function folderNameFromCwd(cwd: string): string {
   const trimmed = cwd.trim().replace(/[\\/]+$/, '');

src/pages/chat/ChatOutlineRail.test.ts

@@ -94,17 +94,21 @@ describe('ChatOutlineRail visibility gates', () => {
       { turn: 2, agents: [] },
       { turn: 3, agents: [] },
     ];
-    expect(hasOutline(renderRail({ turns: oneUser, measuredWidth: 800, enabled: true }))).toBe(false);
-    expect(renderRail({ turns: oneUser, measuredWidth: 800, enabled: true })).toBe('');
+    const html = renderRail({ turns: oneUser, measuredWidth: 800, enabled: true });
+    expect(hasOutline(html)).toBe(false);
+    expect(html).toContain('data-chat-outline-measure');
+    expect(html).not.toContain('role="tablist"');
   });
 
-  it('returns nothing when the setting is off or there are fewer than two user messages', () => {
+  it('returns nothing when the setting is off, and keeps a measure host for one user message', () => {
     expect(renderRail({
       turns: turns('first', 'second'),
       measuredWidth: 800,
       enabled: false,
     })).toBe('');
-    expect(renderRail({ turns: turns('only one'), measuredWidth: 800 })).toBe('');
+    const one = renderRail({ turns: turns('only one'), measuredWidth: 800 });
+    expect(hasOutline(one)).toBe(false);
+    expect(one).toContain('data-chat-outline-measure');
   });
 
   describe('stored preference when enabled is omitted', () => {
@@ -139,8 +143,9 @@ describe('ChatOutlineRail visibility gates', () => {
 });
 
 describe('ChatOutlineRail markup', () => {
-  it('does not draw a rail for one user message', () => {
+  it('keeps the measure host mounted for one user message so width can attach', () => {
     const html = renderRail({ turns: turns('only one'), measuredWidth: 800 });
+    expect(html).toContain('data-chat-outline-measure');
     expect(html).not.toContain('chat-outline-rail');
     expect(html).not.toContain('role="tablist"');
   });
@@ -150,12 +155,22 @@ describe('ChatOutlineRail markup', () => {
     expect(html).toContain('data-testid="chat-outline-rail"');
     expect(html).toContain('role="tablist"');
     expect(html).toContain('role="tab"');
+    expect(html).toContain('type="button"');
     expect(html).toContain('data-testid="chat-outline-tick-u1"');
     expect(html).toContain('data-testid="chat-outline-tick-u2"');
     expect(html).toContain('1 / 2：first');
     expect(html).toContain('2 / 2：second');
   });
 
+  it('does not treat a zero-width empty host as a mounted rail', () => {
+    const html = renderRail({ turns: turns('first', 'second'), measuredWidth: 0 });
+    expect(html).toContain('data-chat-outline-measure');
+    expect(html).not.toContain('chat-outline-rail');
+    expect(html).not.toContain('role="tablist"');
+    expect(html).not.toContain('role="tab"');
+    expect(html).not.toContain('chat-outline-tick-');
+  });
+
   it('hides the rail when the panel is narrower than 720px', () => {
     const html = renderRail({ turns: turns('first', 'second'), measuredWidth: 719 });
     expect(html).not.toContain('chat-outline-rail');

src/pages/chat/ChatOutlineRail.tsx

@@ -3,7 +3,6 @@ import {
   useCallback,
   useEffect,
   useMemo,
-  useRef,
   useState,
   type MouseEvent,
   type PointerEvent,
@@ -16,9 +15,12 @@ import type { TurnGroup } from './chat-format';
 import { createChatOutlineHoverIntent } from './chat-outline-hover';
 import {
   OUTLINE_READING_LINE_PX,
+  outlinePanelElement,
+  outlinePanelWidthReady,
   outlinePromptsFromTurns,
   outlineTickSize,
   promptTickMagnification,
+  readOutlinePanelWidth,
   resolveActivePromptId,
   shouldShowChatOutline,
   type ChatOutlinePrompt,
@@ -47,8 +49,12 @@ export function ChatOutlineRail({
   const [prefEnabled] = useState(loadChatOutlineEnabled);
   const isEnabled = enabled ?? prefEnabled;
   const [observedWidth, setObservedWidth] = useState(0);
-  const panelWidth = measuredWidth ?? observedWidth;
-  const measureRef = useRef<HTMLDivElement>(null);
+  const hasMeasuredWidth = outlinePanelWidthReady(measuredWidth);
+  const panelWidth = hasMeasuredWidth ? measuredWidth : observedWidth;
+  const [measureNode, setMeasureNode] = useState<HTMLDivElement | null>(null);
+  const assignMeasureRef = useCallback((node: HTMLDivElement | null) => {
+    setMeasureNode((prev) => (prev === node ? prev : node));
+  }, []);
   const [hoveredIndex, setHoveredIndex] = useState<number | null>(null);
   const [focusedIndex, setFocusedIndex] = useState<number | null>(null);
   const [activeId, setActiveId] = useState<string | null>(null);
@@ -67,15 +73,22 @@ export function ChatOutlineRail({
   useEffect(() => () => hoverIntent.dispose(), [hoverIntent]);
 
   useEffect(() => {
-    if (measuredWidth != null) return;
-    const node = measureRef.current;
-    if (!node || typeof ResizeObserver === 'undefined') return;
-    const apply = () => setObservedWidth(node.getBoundingClientRect().width);
-    const observer = new ResizeObserver(apply);
-    observer.observe(node);
+    if (hasMeasuredWidth) return;
+    const node = measureNode;
+    if (!node) return;
+    const apply = () => {
+      const next = readOutlinePanelWidth(node);
+      setObservedWidth((prev) => (prev === next ? prev : next));
+    };
     apply();
+    if (typeof ResizeObserver === 'undefined') {
+      window.addEventListener('resize', apply);
+      return () => window.removeEventListener('resize', apply);
+    }
+    const observer = new ResizeObserver(apply);
+    observer.observe(outlinePanelElement(node) ?? node);
     return () => observer.disconnect();
-  }, [measuredWidth]);
+  }, [hasMeasuredWidth, measureNode]);
 
   const readActivePrompt = useCallback(() => {
     const container = scrollRef?.current;
@@ -134,10 +147,14 @@ export function ChatOutlineRail({
     if (!visible) hoverIntent.leave();
   }, [hoverIntent, visible]);
 
-  if (!isEnabled || prompts.length < 2) return null;
+  if (!isEnabled) return null;
 
   return (
-    <div ref={measureRef} className="pointer-events-none absolute inset-0">
+    <div
+      ref={assignMeasureRef}
+      className="pointer-events-none absolute inset-0"
+      data-chat-outline-measure
+    >
       {visible ? (
         <div
           role="tablist"

src/pages/chat/ChatSessionRail.test.ts

@@ -224,5 +224,11 @@ describe('ChatSessionRail titles', () => {
     const unsetGroup = html.slice(html.lastIndexOf('data-help="chat-workspace-group"', unsetAt), unsetAt);
     expect(unsetGroup).not.toContain('data-help="chat-workspace-new"');
   });
+
+  it('starts the main new chat without passing the click event as a folder', () => {
+    const src = readFileSync(new URL('./ChatSessionRail.tsx', import.meta.url), 'utf8');
+    expect(src).toContain('onClick={() => onNewChat()}');
+    expect(src).not.toContain('onClick={onNewChat}');
+  });
 });
 

src/pages/chat/ChatTranscript.test.ts

@@ -24,11 +24,11 @@ function conversation(): Conversation {
   };
 }
 
-function userMessage(content: string): ChatMessage {
+function userMessage(content: string, id = 'm-user', turn = 1): ChatMessage {
   return {
-    id: 'm-user',
+    id,
     conversationId: 'c1',
-    turn: 1,
+    turn,
     role: 'user',
     content,
     status: 'ok',
@@ -192,4 +192,86 @@ describe('ChatTranscript surfaces', () => {
     // Unmeasured panel width is 0, so the 720px gate still hides the ticks.
     expect(html).not.toContain('data-testid="chat-outline-rail"');
   });
+
+  it('mounts the outline rail when the setting, two prompts, and a 720px panel hold', () => {
+    const html = renderMarkup(
+      createElement(ChatTranscript, {
+        active: conversation(),
+        turns: [
+          { turn: 1, user: userMessage('first prompt', 'u1', 1), agents: [] },
+          { turn: 2, user: userMessage('second prompt', 'u2', 2), agents: [] },
+        ],
+        processMap: {},
+        listLoading: false,
+        messagesLoading: false,
+        sending: false,
+        retryDisabled: false,
+        scrollRef: createRef<HTMLDivElement>(),
+        bottomRef: createRef<HTMLDivElement>(),
+        onScroll: () => undefined,
+        onRetry: () => undefined,
+        measuredWidth: 720,
+        outlineEnabled: true,
+      }),
+    );
+    expect(html).toContain('data-testid="chat-outline-rail"');
+    expect(html).toContain('role="tablist"');
+    expect(html).toContain('role="tab"');
+    expect(html).toContain('type="button"');
+    expect(html).toContain('data-testid="chat-outline-tick-u1"');
+    expect(html).toContain('data-testid="chat-outline-tick-u2"');
+    expect(html).toContain('1 / 2：first prompt');
+    expect(html).toContain('2 / 2：second prompt');
+    expect(html).toContain('data-chat-outline-host');
+  });
+
+  it('does not count an empty measure host as the outline', () => {
+    const html = renderMarkup(
+      createElement(ChatTranscript, {
+        active: conversation(),
+        turns: [
+          { turn: 1, user: userMessage('first prompt', 'u1', 1), agents: [] },
+          { turn: 2, user: userMessage('second prompt', 'u2', 2), agents: [] },
+        ],
+        processMap: {},
+        listLoading: false,
+        messagesLoading: false,
+        sending: false,
+        retryDisabled: false,
+        scrollRef: createRef<HTMLDivElement>(),
+        bottomRef: createRef<HTMLDivElement>(),
+        onScroll: () => undefined,
+        onRetry: () => undefined,
+        measuredWidth: 0,
+        outlineEnabled: true,
+      }),
+    );
+    expect(html).toContain('data-chat-outline-host');
+    expect(html).toContain('data-chat-outline-measure');
+    expect(html).not.toContain('chat-outline-rail');
+    expect(html).not.toContain('role="tablist"');
+    expect(html).not.toContain('chat-outline-tick-');
+  });
+
+  it('does not mount the rail ticks when only one user message exists', () => {
+    const html = renderMarkup(
+      createElement(ChatTranscript, {
+        active: conversation(),
+        turns: [{ turn: 1, user: userMessage('only one', 'u1'), agents: [] }],
+        processMap: {},
+        listLoading: false,
+        messagesLoading: false,
+        sending: false,
+        retryDisabled: false,
+        scrollRef: createRef<HTMLDivElement>(),
+        bottomRef: createRef<HTMLDivElement>(),
+        onScroll: () => undefined,
+        onRetry: () => undefined,
+        measuredWidth: 900,
+        outlineEnabled: true,
+      }),
+    );
+    expect(html).toContain('data-chat-outline-host');
+    expect(html).not.toContain('chat-outline-rail');
+  });
 });