diff --git a/packages/extension/src/content/widget/panel.tsx b/packages/extension/src/content/widget/panel.tsx
index c48cc04..e312ea3 100644
--- a/packages/extension/src/content/widget/panel.tsx
+++ b/packages/extension/src/content/widget/panel.tsx
@@ -1,5 +1,5 @@
 import { useCallback, useEffect, useState } from "react";
-import { X, Minus, ExternalLink } from "lucide-react";
+import { X, Minus, ExternalLink, MessageSquarePlus } from "lucide-react";
 import { ChatView } from "@/sidepanel/components/chat-view";
 import { EmptySuggestions } from "@/sidepanel/chat/empty-suggestions";
 import { InputBox } from "@/sidepanel/input/input-box";
@@ -69,6 +69,20 @@ export function Panel({ onClose, onMinimize }: Props) {
     await rpc.widgetOpenSidepanel({ tabId }).catch(() => {});
   }
 
+  async function handleNewChat() {
+    if (!tabId) return;
+    const hasContent =
+      session.messages.length > 0 || session.streamingAssistantText.length > 0;
+    if (hasContent && !window.confirm("新建对话会归档当前会话,确定?")) return;
+    try {
+      const { newChatForTab } = await import("@/sidepanel/chat/new-chat");
+      await newChatForTab(tabId);
+      setInput("");
+    } catch (e) {
+      console.warn("[atwebpilot-widget] newChat failed:", e);
+    }
+  }
+
   const handleApprove = useCallback(
     (
       id: string,
@@ -103,6 +117,13 @@ export function Panel({ onClose, onMinimize }: Props) {
       {/* Header */}
       <header className="flex items-center gap-2 px-3 py-2 border-b border-zinc-800 text-xs shrink-0">
         <b className="flex-1 select-none">⚡ AtWebPilot</b>
+        <button
+          className="p-1 hover:bg-zinc-800 rounded"
+          title="新建对话"
+          onClick={handleNewChat}
+        >
+          <MessageSquarePlus size={14} />
+        </button>
         <button
           className="p-1 hover:bg-zinc-800 rounded"
           title="打开扩展面板"
diff --git a/packages/extension/src/sidepanel/chat/cross-tab-events.ts b/packages/extension/src/sidepanel/chat/cross-tab-events.ts
index 5832d4d..b5e69c1 100644
--- a/packages/extension/src/sidepanel/chat/cross-tab-events.ts
+++ b/packages/extension/src/sidepanel/chat/cross-tab-events.ts
@@ -18,11 +18,19 @@ export function handleTabEvent(ev: TabEvent): void {
           sid === ev.openerTabId ||
           s.attachedTabs.some((a) => a.tabId === ev.openerTabId);
         if (!owns) continue;
-        // Only attribute opener-matched spawns to AI when the session is
-        // actively running. Otherwise the user opened the tab manually
-        // (Ctrl/middle/right-click on a link in the session tab), and
-        // chrome.tabs.create from the openTab tool doesn't set openerTabId.
-        if (s.status !== "running" && s.status !== "streaming") continue;
+        // Only attribute opener-matched spawns to AI when a tool JUST ran
+        // (within the last 1500ms). The prior `status ∈ {running, streaming}`
+        // gate was too loose — during a widget/sidepanel run the sidepanel
+        // saw broadcast status="streaming" even while the AI was quiescent
+        // between rounds, so a user Ctrl+click on the page got misattributed.
+        //
+        // AI's `openTab` tool uses `chrome.tabs.create` (no opener). The only
+        // AI-caused spawn with openerTabId is a `click` tool hitting a
+        // target=_blank link — which fires within milliseconds of tool_running.
+        const now = Date.now();
+        const recentAi =
+          s._lastToolRunningAt != null && now - s._lastToolRunningAt < 1500;
+        if (!recentAi) continue;
         attachTab(sid, {
           tabId: ev.tabId,
           windowId: ev.windowId,
diff --git a/packages/extension/src/sidepanel/chat/new-chat.ts b/packages/extension/src/sidepanel/chat/new-chat.ts
new file mode 100644
index 0000000..9878e19
--- /dev/null
+++ b/packages/extension/src/sidepanel/chat/new-chat.ts
@@ -0,0 +1,32 @@
+/**
+ * "新建对话" 共用流程。sidepanel header 的 [+] 按钮和 widget panel header
+ * 的 [+] 按钮都走这里,保证归档/清理路径一致。
+ *
+ * 1. flush 所有待落盘的 persist 队列(避免半写状态)
+ * 2. 当前 tab 若有 active session,archive 到 IDB(可从历史 drawer 恢复)
+ * 3. 该 URL 下的 archived 会话 pruning(每 URL ≤20)+ cascade 删对应 runs
+ * 4. startNewSession(tabId)
+ * 5. 清 auto-persist 的追踪状态
+ *
+ * 调用方自行清空自己的输入框 draft(sidepanel / widget 各持一份)。
+ */
+import { startNewSession } from "./session-store";
+import {
+  archiveActive,
+  cascadeDeleteRuns,
+  getActiveByTabId,
+  pruneOverLimit,
+} from "./persistence/sessions-storage";
+import { flushAllPending, clearPersistStateFor } from "./persistence/auto-persist";
+
+export async function newChatForTab(tabId: number): Promise<void> {
+  await flushAllPending();
+  const cur = await getActiveByTabId(tabId);
+  if (cur) {
+    await archiveActive(cur.id);
+    const evicted = await pruneOverLimit(cur.url);
+    if (evicted.length) await cascadeDeleteRuns(evicted);
+  }
+  startNewSession(tabId);
+  clearPersistStateFor(tabId);
+}
diff --git a/packages/extension/src/sidepanel/chat/session-store.ts b/packages/extension/src/sidepanel/chat/session-store.ts
index ace6b7c..aac785f 100644
--- a/packages/extension/src/sidepanel/chat/session-store.ts
+++ b/packages/extension/src/sidepanel/chat/session-store.ts
@@ -97,6 +97,12 @@ export type SessionData = {
   chatMode: "compact" | "full";
   /** 广播冲突仲裁字段；每次 mutation 后自增（Task 7）。初始 0。 */
   _rev: number;
+  /**
+   * 最近一次 tool_running 事件的时间戳（Date.now()）。cross-tab-events
+   * 用来判定新 spawn 的 tab 是否 AI 打开的:只有窗口 <1500ms 内有过
+   * tool_running 才归 AI,否则一律视为用户 Ctrl+click。
+   */
+  _lastToolRunningAt?: number;
 };
 
 export function makeEmptySession(tabId: number, url = ""): SessionData {
@@ -339,7 +345,14 @@ export function addLlmExchange(tabId: number, ex: LlmExchange): void {
 }
 
 export function setStatus(tabId: number, status: SessionStatus): void {
-  mutateSession(tabId, (s) => ({ ...s, status }));
+  mutateSession(tabId, (s) => ({
+    ...s,
+    status,
+    // Stamp AI-activity time when a tool starts running. cross-tab-events
+    // uses this to distinguish AI-opened tabs from user Ctrl+click (both
+    // arrive with `openerTabId` set;only recent AI activity attributes AI).
+    ...(status === "running" ? { _lastToolRunningAt: Date.now() } : {}),
+  }));
 }
 
 export function setError(tabId: number, errorMessage: string | null): void {
diff --git a/packages/extension/src/sidepanel/shell/app-shell.tsx b/packages/extension/src/sidepanel/shell/app-shell.tsx
index 20ef563..028980f 100644
--- a/packages/extension/src/sidepanel/shell/app-shell.tsx
+++ b/packages/extension/src/sidepanel/shell/app-shell.tsx
@@ -23,18 +23,11 @@ import {
   setPermissionMode,
   setChatMode,
   setDebugBadge,
-  startNewSession,
   useCurrentTabId,
   useSession,
   useStore,
 } from "@/sidepanel/chat/session-store";
-import {
-  archiveActive,
-  cascadeDeleteRuns,
-  getActiveByTabId,
-  pruneOverLimit,
-} from "@/sidepanel/chat/persistence/sessions-storage";
-import { flushAllPending, clearPersistStateFor } from "@/sidepanel/chat/persistence/auto-persist";
+import { getActiveByTabId } from "@/sidepanel/chat/persistence/sessions-storage";
 import { handleTabEvent } from "@/sidepanel/chat/cross-tab-events";
 import { useSettings, installSettingsSyncListener } from "@/sidepanel/chat/settings-store";
 import { useUi } from "@/sidepanel/chat/ui-store";
@@ -645,15 +638,8 @@ export function AppShell() {
   async function onNewChat() {
     const tabId = useStore.getState().currentTabId;
     if (tabId == null) return;
-    await flushAllPending();
-    const cur = await getActiveByTabId(tabId);
-    if (cur) {
-      await archiveActive(cur.id);
-      const evicted = await pruneOverLimit(cur.url);
-      if (evicted.length) await cascadeDeleteRuns(evicted);
-    }
-    startNewSession(tabId);
-    clearPersistStateFor(tabId);
+    const { newChatForTab } = await import("@/sidepanel/chat/new-chat");
+    await newChatForTab(tabId);
     setInput("");
   }
 
diff --git a/packages/extension/tests/sidepanel/chat/cross-tab-events.test.ts b/packages/extension/tests/sidepanel/chat/cross-tab-events.test.ts
index d7e1110..8319c9c 100644
--- a/packages/extension/tests/sidepanel/chat/cross-tab-events.test.ts
+++ b/packages/extension/tests/sidepanel/chat/cross-tab-events.test.ts
@@ -89,7 +89,9 @@ describe("handleTabEvent", () => {
 
   it("tabs.spawned auto-attaches to session whose attached tab is opener", () => {
     ensureSession(100, "https://main");
-    setStatus(100, "streaming");
+    // "running" stamps _lastToolRunningAt (recent tool activity),
+    // which is what actually gates AI-attribution now.
+    setStatus(100, "running");
     attachTab(100, {
       tabId: 150, windowId: 1, source: "mention", lastSeenUrl: "u", lastSeenTitle: "t"
     });
@@ -105,6 +107,39 @@ describe("handleTabEvent", () => {
     expect(a.find((x) => x.tabId === 200)).toMatchObject({ source: "ai-open" });
   });
 
+  it("tabs.spawned during streaming (but no recent tool activity) is NOT attributed to AI", () => {
+    // Regression test for the widget-era misattribution: user Ctrl+click on a
+    // link during AI text-streaming (between tool runs) used to attach the
+    // new tab as `ai-open`. Now attribution requires a tool_running event
+    // within the last 1500ms.
+    ensureSession(100, "https://main");
+    setCurrentTab(100);
+    // Simulate: AI ran a tool a while ago, now just streaming text.
+    useStore.setState((state) => ({
+      ...state,
+      sessionsByTab: {
+        ...state.sessionsByTab,
+        100: {
+          ...state.sessionsByTab[100],
+          status: "streaming",
+          _lastToolRunningAt: Date.now() - 5000, // 5 s ago — stale
+          messages: [{ role: "user", content: "hi" }]
+        }
+      }
+    }));
+    handleTabEvent({
+      type: "tabs.spawned",
+      tabId: 200,
+      openerTabId: 100,
+      windowId: 1,
+      url: "https://child",
+      title: "Child"
+    });
+    expect(getSessionFor(100).attachedTabs).toEqual([]);
+    const last = getSessionFor(100).messages.at(-1);
+    expect(JSON.stringify(last)).not.toMatch(/AI 在 #200/);
+  });
+
   it("tabs.urlChanged on an attached tab sets urlChanged", () => {
     ensureSession(100, "https://main");
     attachTab(100, {