fix(desktop): simplify partial history notice

apps/desktop/e2e/fixtures.ts

@@ -482,6 +482,7 @@ export const test = base.extend<{
   parentRemovalWindow: Page;
   railRenderWindow: Page;
   promptRailWindow: Page;
+  partialHistoryWindow: Page;
   promptRailMotionWindow: Page;
   requestHeaderRowWindow: Page;
   newTaskTargetWindow: Page;
@@ -588,6 +589,17 @@ export const test = base.extend<{
       showWindow: true,
     }, use);
   },
+  // A transcript larger than the bounded Desktop range. Clicking an unloaded
+  // prompt exercises the real load-around path and its partial-history UI.
+  partialHistoryWindow: async ({}, use) => {
+    await withE2eWindow({
+      seed: false,
+      readinessSelector: '[data-turn-id]',
+      e2eFixtureScenario: 'chat-partial-history',
+      locale: 'zh',
+      showWindow: true,
+    }, use);
+  },
   // The same transcript, scrolling the way the shipped app scrolls. Separate
   // from `promptRailWindow` because it is only the jump that needs a scroll
   // still in flight, and paying for one everywhere costs several seconds per

apps/desktop/e2e/partial-history-notice.spec.ts

@@ -0,0 +1,137 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import type { Page } from '@playwright/test';
+import { expect, test } from './fixtures';
+
+const NOTICE = '.maka-transcript-history-controls';
+
+async function waitForPaint(page: Page): Promise<void> {
+  await page.evaluate(() => new Promise<void>((resolve) => {
+    requestAnimationFrame(() => requestAnimationFrame(() => resolve()));
+  }));
+}
+
+async function noticePresentation(page: Page) {
+  return page.locator(NOTICE).evaluate((notice) => {
+    const style = getComputedStyle(notice);
+    const box = notice.getBoundingClientRect();
+    const composer = document.querySelector('.maka-composer-astryx');
+    if (!composer) throw new Error('the composer is missing');
+    const composerBox = composer.getBoundingClientRect();
+    return {
+      backgroundColor: style.backgroundColor,
+      borderWidths: [
+        style.borderTopWidth,
+        style.borderRightWidth,
+        style.borderBottomWidth,
+        style.borderLeftWidth,
+      ],
+      display: style.display,
+      flexWrap: style.flexWrap,
+      justifyContent: style.justifyContent,
+      widthDelta: Math.abs(box.width - composerBox.width),
+      centerDelta: Math.abs(
+        (box.left + box.right) / 2 - (composerBox.left + composerBox.right) / 2,
+      ),
+      fitsViewport: box.left >= 0 && box.right <= document.documentElement.clientWidth,
+      hasHorizontalOverflow: notice.scrollWidth > notice.clientWidth,
+    };
+  });
+}
+
+test('partial history is a quiet reading-column control with neutral rail ticks', async ({
+  partialHistoryWindow: page,
+}) => {
+  await page.setViewportSize({ width: 1_400, height: 800 });
+  await expect(page.locator(NOTICE)).toHaveCount(0);
+
+  const firstPrompt = page.locator(
+    '.maka-prompt-rail-tick[data-prompt-turn-id="turn-partial-history-1"]',
+  );
+  await expect(firstPrompt).toBeVisible();
+  await firstPrompt.click();
+
+  const notice = page.locator(NOTICE);
+  await expect(notice).toBeVisible();
+  await expect(notice).toContainText('正在查看较早的消息');
+  await expect(notice.getByRole('button', { name: '返回最新消息' })).toBeVisible();
+  await expect(notice).not.toContainText(/保存|加载/);
+
+  const regular = await noticePresentation(page);
+  expect(regular).toEqual({
+    backgroundColor: 'rgba(0, 0, 0, 0)',
+    borderWidths: ['0px', '0px', '0px', '0px'],
+    display: 'flex',
+    flexWrap: 'wrap',
+    justifyContent: 'center',
+    widthDelta: expect.any(Number),
+    centerDelta: expect.any(Number),
+    fitsViewport: true,
+    hasHorizontalOverflow: false,
+  });
+  expect(regular.widthDelta).toBeLessThanOrEqual(1);
+  expect(regular.centerDelta).toBeLessThanOrEqual(1);
+
+  await page.mouse.move(0, 0);
+  await page.evaluate(() => (document.activeElement as HTMLElement | null)?.blur());
+  const railPresentation = await page.evaluate(() => {
+    const ticks = [...document.querySelectorAll<HTMLElement>('.maka-prompt-rail-tick')];
+    const presentation = (tick: HTMLElement) => {
+      const bar = tick.querySelector<HTMLElement>('.maka-prompt-rail-tick-bar');
+      if (!bar) throw new Error('a prompt rail tick is missing its bar');
+      const style = getComputedStyle(bar);
+      return {
+        backgroundColor: style.backgroundColor,
+        borderStyle: style.borderStyle,
+        borderWidth: style.borderWidth,
+        boxShadow: style.boxShadow,
+      };
+    };
+    const neutralPaint = ticks
+      .filter((tick) => tick.dataset.active !== 'true' && !tick.matches(':hover'))
+      .map(presentation);
+    const residentStyleRules = [...document.styleSheets].flatMap((sheet) =>
+      [...sheet.cssRules].filter((rule) => rule.cssText.includes('data-resident'))
+    );
+    return {
+      residentAttributeCount: document.querySelectorAll('[data-resident]').length,
+      residentStyleRuleCount: residentStyleRules.length,
+      neutralTickCount: neutralPaint.length,
+      neutralPaintCount: new Set(neutralPaint.map((paint) => JSON.stringify(paint))).size,
+    };
+  });
+  expect(railPresentation.residentAttributeCount).toBe(0);
+  expect(railPresentation.residentStyleRuleCount).toBe(0);
+  expect(railPresentation.neutralTickCount).toBeGreaterThan(1);
+  expect(railPresentation.neutralPaintCount).toBe(1);
+
+  await page.setViewportSize({ width: 520, height: 720 });
+  await waitForPaint(page);
+  const narrow = await noticePresentation(page);
+  expect(narrow.centerDelta).toBeLessThanOrEqual(1);
+  expect(narrow.fitsViewport).toBe(true);
+  expect(narrow.hasHorizontalOverflow).toBe(false);
+
+  await notice.getByRole('button', { name: '返回最新消息' }).click();
+  await expect(notice).toHaveCount(0);
+  await expect(
+    page.locator('[data-turn-id="turn-partial-history-8"]'),
+  ).toBeVisible();
+});

apps/desktop/src/main/e2e-fixture.ts

@@ -34,11 +34,14 @@ import {
   LONG_SIDEBAR_PROJECT_ID,
   LONG_SIDEBAR_PROJECT_NAME,
   LONG_SIDEBAR_SESSION_PREFIX,
+  PARTIAL_HISTORY_SESSION_ID,
   PROMPT_RAIL_SESSION_ID,
   TURN_SESSION_ID,
   writeSession,
 } from './e2e-fixture/seed-helpers.js';
 import {
+  partialHistoryMessages,
+  partialHistorySession,
   promptRailMessages,
   promptRailSession,
   turnMessages,
@@ -59,6 +62,7 @@ const E2E_FIXTURE_SCENARIOS = new Set<E2eFixtureScenario>([
   'turn-narrative',
   'turn-narrative-browser',
   'chat-prompt-rail',
+  'chat-partial-history',
   'settings-data',
   'settings-bots-onboarding',
   'settings-general',
@@ -174,6 +178,8 @@ export function getE2eFixtureState(fixture: E2eFixture | null): E2eFixtureState
       // this window scrolls smoothly is a per-launch choice (`scrollMotion`),
       // because only the jump case needs it and it costs seconds of settling.
       return { ...state, activeSessionId: PROMPT_RAIL_SESSION_ID, workbarCollapsed: true };
+    case 'chat-partial-history':
+      return { ...state, activeSessionId: PARTIAL_HISTORY_SESSION_ID, workbarCollapsed: true };
     case 'settings-data':
       return { ...state, activeSessionId: TURN_SESSION_ID, openSettingsSection: 'data' };
     case 'settings-bots-onboarding':
@@ -225,6 +231,13 @@ export async function seedE2eFixture(input: {
   if (scenario === 'chat-prompt-rail') {
     await writeSession(input.workspaceRoot, promptRailSession(now), promptRailMessages(now));
   }
+  if (scenario === 'chat-partial-history') {
+    await writeSession(
+      input.workspaceRoot,
+      partialHistorySession(now),
+      partialHistoryMessages(now),
+    );
+  }
   if (scenario === 'sidebar-search-modal-open') {
     for (const seed of longSidebarSessions(now)) {
       await writeSession(input.workspaceRoot, seed.header, seed.messages);

apps/desktop/src/main/e2e-fixture/scenarios-chat.ts

@@ -20,6 +20,7 @@
 import type { SessionHeader, StoredMessage } from '@maka/core/session';
 import {
   header,
+  PARTIAL_HISTORY_SESSION_ID,
   PROMPT_RAIL_PROMPT_COUNT,
   PROMPT_RAIL_SESSION_ID,
   TURN_SESSION_ID,
@@ -148,3 +149,45 @@ export function promptRailMessages(now: number): StoredMessage[] {
   }
   return messages;
 }
+
+export function partialHistorySession(now: number): SessionHeader {
+  return header({
+    id: PARTIAL_HISTORY_SESSION_ID,
+    name: '超长对话历史范围示例',
+    connection: 'zai-live',
+    model: 'glm-5.1',
+    now,
+    lastMessageAt: now - 60_000,
+  });
+}
+
+/**
+ * Eight turns whose durable transcript is well over the Desktop range budget.
+ * The whitespace is stored but collapses when rendered, keeping this a useful
+ * visual fixture while forcing the initial open to contain only the latest
+ * contiguous range.
+ */
+export function partialHistoryMessages(now: number): StoredMessage[] {
+  const messages: StoredMessage[] = [];
+  const rangePadding = ' '.repeat(180 * 1024);
+  for (let index = 1; index <= 8; index += 1) {
+    const turnId = `turn-partial-history-${index}`;
+    const ts = now - (9 - index) * 60_000;
+    messages.push({
+      type: 'user',
+      id: `msg-partial-history-user-${index}`,
+      turnId,
+      ts,
+      text: `第 ${index} 个问题：请概括这一阶段的实现进展。`,
+    });
+    messages.push({
+      type: 'assistant',
+      id: `msg-partial-history-assistant-${index}`,
+      turnId,
+      ts: ts + 1_000,
+      text: `第 ${index} 阶段已经完成关键实现，并通过了对应验证。${rangePadding}`,
+      modelId: 'glm-5.1',
+    });
+  }
+  return messages;
+}

apps/desktop/src/main/e2e-fixture/seed-helpers.ts

@@ -34,6 +34,7 @@ export const E2E_FIXTURE_NOW = Date.UTC(2026, 4, 22, 3, 0, 0);
 
 export const TURN_SESSION_ID = 'e2e-fixture-turn';
 export const PROMPT_RAIL_SESSION_ID = 'e2e-fixture-prompt-rail';
+export const PARTIAL_HISTORY_SESSION_ID = 'e2e-fixture-partial-history';
 /** Exceeds both the 64-tick rail and 100-turn mounted-window bounds. */
 export const PROMPT_RAIL_PROMPT_COUNT = 120;
 export const LONG_SIDEBAR_SESSION_PREFIX = 'e2e-fixture-sidebar-long-';

apps/desktop/src/renderer/chat-message-surface.tsx

@@ -249,7 +249,6 @@ export function ChatMessageSurface({
         onLoadEarlierHistory={onLoadEarlierHistory}
         returnToLatest={hasNewerHistory ? {
           title: transcriptCopy.partialHistoryTitle,
-          description: transcriptCopy.partialHistoryDescription,
           label: transcriptCopy.returnLatest,
           isPending: historyLoadPending,
           onClick: onReturnToLatestHistory,