feat: 完善多账号连接诊断与聊天媒体导出

- 新增微信账号发现、环境诊断和分步数据库连接引导 - 支持按账号安全保存数据库密钥及快速切换账号 - 完善 WCDB 历史消息分片读取和分页状态提示 - 支持导出图片、视频和语音，提供原图优先及缩略图回退 - 更新安装指引、兼容版本说明和相关自动化测试
2026-08-17 03:27:00 +08:00 · 2026-08-03 10:43:14 +08:00
parent 224308f0e0
commit 08e1294e5d
37 changed files with 2011 additions and 255 deletions
@@ -197,10 +197,18 @@ WechatExplorer 希望不仅仅是一个聊天记录查看工具，更希望成

 ### 下载并安装

-从 [GitHub Releases](https://github.com/Wxw-Gu/WechatExplorer/releases) 下载对应系统的安装包：
+当前 WechatExplorer / 迹忆版本：`v2.1.6`。

- Windows：下载 `-setup.exe` 并按安装向导完成安装。
- macOS：下载 `.dmg`，将 WechatExplorer 拖入“应用程序”。首次打开若被系统拦截，请在“系统设置 → 隐私与安全性”中允许打开。
+应用安装包：[WechatExplorer GitHub Releases](https://github.com/Wxw-Gu/WechatExplorer/releases)。Windows 选择 `-setup.exe`，macOS 按处理器架构选择对应 `.dmg`。
+
+| 系统    | 已测试的微信客户端                                                                                |
+| ------- | ------------------------------------------------------------------------------------------------- |
+| Windows | [微信 Windows `4.1.9.57`](https://github.com/iibob/wechat-win-archive/releases#release-v4.1.9.57) |
+| macOS   | [微信 macOS `4.1.8.100`](https://github.com/zsbai/wechat-versions/releases/tag/4.1.8.100)         |
+
+微信客户端来自上表对应的第三方版本存档，请自行核对来源与文件完整性。
+
+正常覆盖安装只会替换应用程序文件，WechatExplorer / 迹忆不会主动删除或修改微信原始聊天记录；但应用缓存和本地设置可能随版本升级变化。升级前仍建议使用微信官方迁移或备份功能备份重要记录，不要将唯一副本保存在单一设备。

 ### 连接微信

@@ -13,12 +13,14 @@
 - [我遇到问题](#遇到问题)
 - [我想让 Agent 读取微信](#接入-api-reader-skill-或-agent)

+> 正常覆盖安装只会替换应用程序文件，WechatExplorer / 迹忆不会主动删除或修改微信原始聊天记录。应用缓存和本地设置可能随版本升级发生变化。系统故障、磁盘异常、误操作和微信自身迁移不受本应用控制，因此升级前仍建议使用微信官方迁移或备份功能备份重要聊天记录，不要将唯一副本保存在单一设备。
+
 ## 开始前确认

-| 系统 | 已测试的微信版本 | 需要注意 |
-| --- | --- | --- |
-| macOS | `4.1.8.100` | 自动获取数据库密钥前需要关闭 SIP 并完成授权 |
-| Windows | `4.1.9.57` | 已完整支持；首次使用时请确认微信数据目录 |
+| 系统    | 已测试的微信客户端                                                                                | 需要注意                                    |
+| ------- | ------------------------------------------------------------------------------------------------- | ------------------------------------------- |
+| macOS   | [微信 macOS `4.1.8.100`](https://github.com/zsbai/wechat-versions/releases/tag/4.1.8.100)         | 自动获取数据库密钥前需要关闭 SIP 并完成授权 |
+| Windows | [微信 Windows `4.1.9.57`](https://github.com/iibob/wechat-win-archive/releases#release-v4.1.9.57) | 已完整支持；首次使用时请确认微信数据目录    |

 - WechatExplorer 当前面向微信 4.0 数据结构。
 - Windows 不需要关闭 SIP。
@@ -26,7 +28,7 @@
 - WechatExplorer 必须取得当前微信账号对应的数据库密钥才能读取聊天记录。
 - 请只处理你有权访问的微信数据。

-下载入口：[GitHub Releases](https://github.com/Wxw-Gu/WechatExplorer/releases)
+WechatExplorer / 迹忆应用安装包：[GitHub Releases](https://github.com/Wxw-Gu/WechatExplorer/releases)。Windows 选择 `-setup.exe`，macOS 按处理器架构选择对应 `.dmg`。微信客户端请使用上方“已测试的微信客户端”链接。

 ## 第一次连接微信

@@ -141,7 +143,7 @@ AI 功能使用你配置的模型服务。相关聊天内容会按请求发送
 先判断你遇到的现象，再按对应路径处理。

 | 现象                              | 优先检查                                                 |
-| --- | --- |
+| --------------------------------- | -------------------------------------------------------- |
 | 软件打不开                        | macOS 安全提示或应用损坏处理；Windows 重新运行安装包     |
 | 找不到微信数据                    | 在首次连接页面或设置中确认数据目录，Windows 检查目录层级 |
 | 获取不到数据库密钥                | 微信是否停留在登录页面、微信和应用是否同时运行           |
@@ -1,6 +1,7 @@
 import { app, safeStorage } from 'electron'
 import fs from 'fs-extra'
 import path from 'path'
+import crypto from 'crypto'
 import type { DatabaseKeyStorageResult } from '../shared/database-key'

 const normalizeDatabaseKey = (value: string): string => value.trim().replace(/^0x/i, '')
@@ -9,32 +10,42 @@ export const isValidDatabaseKey = (value: string): boolean =>
  /^[0-9a-f]{64}$/i.test(normalizeDatabaseKey(value))

 export class DatabaseKeyStore {
-  private get filePath(): string {
+  private get legacyFilePath(): string {
    return path.join(app.getPath('userData'), 'wechat-db-key.bin')
  }

-  async getStatus(): Promise<{ saved: boolean; encryptionAvailable: boolean }> {
+  private get directoryPath(): string {
+    return path.join(app.getPath('userData'), 'database-keys')
+  }
+
+  private filePath(accountRoot: string): string {
+    const normalized = path.resolve(accountRoot).toLowerCase()
+    const id = crypto.createHash('sha256').update(normalized).digest('hex')
+    return path.join(this.directoryPath, `${id}.bin`)
+  }
+
+  async getStatus(accountRoot: string): Promise<{ saved: boolean; encryptionAvailable: boolean }> {
    return {
-      saved: await fs.pathExists(this.filePath),
+      saved: Boolean(accountRoot) && (await fs.pathExists(this.filePath(accountRoot))),
      encryptionAvailable: safeStorage.isEncryptionAvailable()
    }
  }

-  async load(): Promise<DatabaseKeyStorageResult> {
+  async load(accountRoot: string): Promise<DatabaseKeyStorageResult> {
    try {
-      const status = await this.getStatus()
+      const status = await this.getStatus(accountRoot)
      if (!status.saved) return { success: true, ...status }
      if (!status.encryptionAvailable) {
        return { success: false, error: '系统安全存储不可用', ...status }
      }
-      const encrypted = await fs.readFile(this.filePath)
+      const encrypted = await fs.readFile(this.filePath(accountRoot))
      const key = normalizeDatabaseKey(safeStorage.decryptString(encrypted))
      if (!isValidDatabaseKey(key)) {
        return { success: false, error: '已保存的密钥格式无效', ...status }
      }
      return { success: true, key, ...status }
    } catch (error) {
-      const status = await this.getStatus()
+      const status = await this.getStatus(accountRoot)
      return {
        success: false,
        error: error instanceof Error ? error.message : String(error),
@@ -43,13 +54,49 @@ export class DatabaseKeyStore {
    }
  }

-  async save(rawKey: string): Promise<DatabaseKeyStorageResult> {
+  async loadLegacy(): Promise<DatabaseKeyStorageResult> {
+    const saved = await fs.pathExists(this.legacyFilePath)
+    const encryptionAvailable = safeStorage.isEncryptionAvailable()
+    if (!saved) return { success: true, saved, encryptionAvailable }
+    if (!encryptionAvailable) {
+      return { success: false, error: '系统安全存储不可用', saved, encryptionAvailable }
+    }
+    try {
+      const key = normalizeDatabaseKey(
+        safeStorage.decryptString(await fs.readFile(this.legacyFilePath))
+      )
+      return isValidDatabaseKey(key)
+        ? { success: true, key, saved, encryptionAvailable }
+        : { success: false, error: '旧版密钥格式无效', saved, encryptionAvailable }
+    } catch (error) {
+      return {
+        success: false,
+        error: error instanceof Error ? error.message : String(error),
+        saved,
+        encryptionAvailable
+      }
+    }
+  }
+
+  async clearLegacy(): Promise<void> {
+    await fs.remove(this.legacyFilePath)
+  }
+
+  async save(accountRoot: string, rawKey: string): Promise<DatabaseKeyStorageResult> {
    const key = normalizeDatabaseKey(rawKey)
+    if (!accountRoot.trim()) {
+      return {
+        success: false,
+        error: '请先选择微信账号',
+        saved: false,
+        encryptionAvailable: safeStorage.isEncryptionAvailable()
+      }
+    }
    if (!isValidDatabaseKey(key)) {
      return {
        success: false,
        error: '密钥必须是 64 位十六进制字符',
-        saved: await fs.pathExists(this.filePath),
+        saved: await fs.pathExists(this.filePath(accountRoot)),
        encryptionAvailable: safeStorage.isEncryptionAvailable()
      }
    }
@@ -57,29 +104,30 @@ export class DatabaseKeyStore {
      return {
        success: false,
        error: '系统安全存储不可用',
-        saved: await fs.pathExists(this.filePath),
+        saved: await fs.pathExists(this.filePath(accountRoot)),
        encryptionAvailable: false
      }
    }

    try {
-      await fs.ensureDir(path.dirname(this.filePath))
-      await fs.writeFile(this.filePath, safeStorage.encryptString(key), { mode: 0o600 })
-      await fs.chmod(this.filePath, 0o600)
+      const filePath = this.filePath(accountRoot)
+      await fs.ensureDir(this.directoryPath)
+      await fs.writeFile(filePath, safeStorage.encryptString(key), { mode: 0o600 })
+      await fs.chmod(filePath, 0o600)
      return { success: true, key, saved: true, encryptionAvailable: true }
    } catch (error) {
      return {
        success: false,
        error: error instanceof Error ? error.message : String(error),
-        saved: await fs.pathExists(this.filePath),
+        saved: await fs.pathExists(this.filePath(accountRoot)),
        encryptionAvailable: true
      }
    }
  }

-  async clear(): Promise<{ success: boolean; error?: string }> {
+  async clear(accountRoot: string): Promise<{ success: boolean; error?: string }> {
    try {
-      await fs.remove(this.filePath)
+      if (accountRoot) await fs.remove(this.filePath(accountRoot))
      return { success: true }
    } catch (error) {
      return { success: false, error: error instanceof Error ? error.message : String(error) }
@@ -1,6 +1,6 @@
 import type { Message } from '../shared/types'

-export const exportStyles = `:root{color-scheme:light;--page:#edf2f0;--panel:#fff;--text:#1d2a25;--muted:#68766f;--border:#d8e2dc;--mine:#d9f0e2;--accent:#176b57}*{box-sizing:border-box}body{margin:0;background:var(--page);color:var(--text);font:14px system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif}.page{max-width:1240px;height:100vh;margin:auto;padding:22px 28px;display:flex;flex-direction:column}.toolbar{display:flex;align-items:center;justify-content:space-between;gap:20px;background:var(--panel);border:1px solid var(--border);border-radius:18px;padding:18px 24px;box-shadow:0 8px 24px #29483b12}.title{font-size:18px;font-weight:750}.meta{color:var(--muted);margin-left:12px;font-size:13px}.controls{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:0}.controls input,.controls button{border:1px solid var(--border);border-radius:10px;padding:9px 12px;background:#fff;font:inherit}.controls input[type=search]{width:260px}.controls input[type=datetime-local],.controls #jump{display:none}.controls button{background:var(--accent);border-color:var(--accent);color:#fff;cursor:pointer}.count{margin-left:8px;color:var(--muted);font-size:13px}.scroll{margin-top:18px;overflow:auto;flex:1;padding:10px 6px 30px;display:flex;flex-direction:column;align-items:center}.message{display:flex;flex-direction:column;gap:6px;width:min(100%,820px);margin:0 0 22px}.message.hidden{display:none}.message.sent{align-items:flex-end;margin-left:auto}.message.system{align-items:center;width:min(100%,820px)}.message.system .row{justify-content:center}.message.system .avatar{display:none}.message.system .bubble{max-width:92%;padding:5px 10px;border:0;border-radius:5px;background:#e9eeeb;color:var(--muted);font-size:11px;text-align:center;box-shadow:none}.message.system .sender{display:none}.time{color:var(--muted);font-size:11px;margin:0 12px}.row{display:flex;gap:12px;align-items:flex-end}.sent .row{flex-direction:row-reverse}.avatar{width:38px;height:38px;flex:0 0 auto;border-radius:50%;overflow:hidden;background:#dcebe4;display:grid;place-items:center}.avatar img{width:100%;height:100%;object-fit:cover}.bubble{max-width:min(78%,760px);padding:13px 15px;border:1px solid var(--border);border-radius:10px 18px 18px 18px;background:#fff;box-shadow:0 4px 12px #29483b0d}.sent .bubble{background:var(--mine);border-color:#c7e6d4;border-radius:18px 10px 18px 18px}.sender{color:var(--muted);font-size:12px;margin-bottom:5px}.content{line-height:1.7;word-break:break-word;white-space:pre-wrap}.audio-wrap{width:260px;min-width:260px}.audio{display:block;width:260px;height:38px}.quote-reference{margin-top:10px;padding:8px 11px;border-left:3px solid #8eb4a3;background:#f1f6f3;color:var(--muted);display:grid;gap:3px}.quote-reference strong{font-weight:650;color:var(--text)}.quote-reference span{white-space:pre-wrap}.media-image{display:block;max-width:100%;max-height:360px;border-radius:12px;object-fit:contain;background:#eef2f5;cursor:zoom-in}.lightbox{position:fixed;inset:0;display:none;place-items:center;background:#14231ddd;z-index:10;padding:24px;overflow:auto}.lightbox.open{display:grid}.lightbox img{width:min(86vw,980px);max-height:88vh;object-fit:contain;cursor:zoom-in;transform:scale(var(--zoom,1));transform-origin:center;transition:transform .12s ease}`
+export const exportStyles = `:root{color-scheme:light;--page:#edf2f0;--panel:#fff;--text:#1d2a25;--muted:#68766f;--border:#d8e2dc;--mine:#d9f0e2;--accent:#176b57}*{box-sizing:border-box}body{margin:0;background:var(--page);color:var(--text);font:14px system-ui,-apple-system,"PingFang SC","Microsoft YaHei",sans-serif}.page{max-width:1240px;height:100vh;margin:auto;padding:22px 28px;display:flex;flex-direction:column}.toolbar{display:flex;align-items:center;justify-content:space-between;gap:20px;background:var(--panel);border:1px solid var(--border);border-radius:18px;padding:18px 24px;box-shadow:0 8px 24px #29483b12}.title{font-size:18px;font-weight:750}.meta{color:var(--muted);margin-left:12px;font-size:13px}.controls{display:flex;gap:8px;align-items:center;flex-wrap:wrap;margin-top:0}.controls input,.controls button{border:1px solid var(--border);border-radius:10px;padding:9px 12px;background:#fff;font:inherit}.controls input[type=search]{width:260px}.controls input[type=datetime-local],.controls #jump{display:none}.controls button{background:var(--accent);border-color:var(--accent);color:#fff;cursor:pointer}.count{margin-left:8px;color:var(--muted);font-size:13px}.scroll{margin-top:18px;overflow:auto;flex:1;padding:10px 6px 30px;display:flex;flex-direction:column;align-items:center}.message{display:flex;flex-direction:column;gap:6px;width:min(100%,820px);margin:0 0 22px}.message.hidden{display:none}.message.sent{align-items:flex-end;margin-left:auto}.message.system{align-items:center;width:min(100%,820px)}.message.system .row{justify-content:center}.message.system .avatar{display:none}.message.system .bubble{max-width:92%;padding:5px 10px;border:0;border-radius:5px;background:#e9eeeb;color:var(--muted);font-size:11px;text-align:center;box-shadow:none}.message.system .sender{display:none}.time{color:var(--muted);font-size:11px;margin:0 12px}.row{display:flex;gap:12px;align-items:flex-end}.sent .row{flex-direction:row-reverse}.avatar{width:38px;height:38px;flex:0 0 auto;border-radius:50%;overflow:hidden;background:#dcebe4;display:grid;place-items:center}.avatar img{width:100%;height:100%;object-fit:cover}.bubble{max-width:min(78%,760px);padding:13px 15px;border:1px solid var(--border);border-radius:10px 18px 18px 18px;background:#fff;box-shadow:0 4px 12px #29483b0d}.sent .bubble{background:var(--mine);border-color:#c7e6d4;border-radius:18px 10px 18px 18px}.sender{color:var(--muted);font-size:12px;margin-bottom:5px}.content{line-height:1.7;word-break:break-word;white-space:pre-wrap}.audio-wrap{width:260px;min-width:260px}.audio{display:block;width:260px;height:38px}.media-status{margin-top:8px;padding:6px 8px;border-left:3px solid #b27a18;background:#fff8e8;color:#79530f;font-size:12px;line-height:1.5}.quote-reference{margin-top:10px;padding:8px 11px;border-left:3px solid #8eb4a3;background:#f1f6f3;color:var(--muted);display:grid;gap:3px}.quote-reference strong{font-weight:650;color:var(--text)}.quote-reference span{white-space:pre-wrap}.media-image{display:block;max-width:100%;max-height:360px;border-radius:12px;object-fit:contain;background:#eef2f5;cursor:zoom-in}.lightbox{position:fixed;inset:0;display:none;place-items:center;background:#14231ddd;z-index:10;padding:24px;overflow:auto}.lightbox.open{display:grid}.lightbox img{width:min(86vw,980px);max-height:88vh;object-fit:contain;cursor:zoom-in;transform:scale(var(--zoom,1));transform-origin:center;transition:transform .12s ease}.lightbox-close{position:fixed;top:20px;right:20px;z-index:11;width:42px;height:42px;border:1px solid #ffffff66;border-radius:50%;background:#14231dcc;color:#fff;font-size:30px;line-height:1;cursor:pointer}`
 const safe = (value: unknown): string =>
  String(value ?? '').replace(
    /[&<>"']/g,
@@ -14,7 +14,10 @@ export function renderExportPage(name: string, messages: Message[]): string {
        ? `<img src="${safe(m.img)}" alt="">`
        : safe((m.name || (m.isSender ? '我' : '友')).slice(0, 1))
      const audio = m.voiceDataUrl
-        ? `<div class="audio-wrap"><audio class="audio" controls preload="metadata" src="${m.voiceDataUrl}"></audio></div>`
+        ? `<div class="audio-wrap"><audio class="audio" controls preload="metadata" src="${safe(m.voiceDataUrl)}"></audio></div>`
+        : ''
+      const mediaStatus = m.exportMediaError
+        ? `<div class="media-status">${safe(m.exportMediaError)}</div>`
        : ''
      const quote =
        m.contentData?.type === 'quote'
@@ -34,8 +37,8 @@ export function renderExportPage(name: string, messages: Message[]): string {
          : `<div class="avatar">${m.exportAvatarUrl ? `<img src="${safe(m.exportAvatarUrl)}" alt="">` : avatar}</div>`
      const isPat = m.contentData?.type === 'system' && m.contentData.pat
      const text = m.content || (m.contentData?.type === 'quote' ? m.contentData.title : '')
-      return `<article class="message${m.isSender ? ' sent' : ''}${isPat ? ' system' : ''}" data-time="${m.createTime || 0}" data-search="${safe(`${m.name || ''} ${m.content || ''} ${m.type}`.toLowerCase())}"><div class="time">${safe(m.datetime)}</div><div class="row">${isPat ? '' : avatarMarkup}<div class="bubble"><div class="sender">${isPat ? '' : safe(m.name || (m.isSender ? '我' : '联系人'))}</div>${media}${audio}${quote}<div class="content">${safe(text || (!media && !audio && !quote ? `[${m.type}]` : ''))}</div></div></div></article>`
+      return `<article class="message${m.isSender ? ' sent' : ''}${isPat ? ' system' : ''}" data-time="${m.createTime || 0}" data-search="${safe(`${m.name || ''} ${m.content || ''} ${m.type}`.toLowerCase())}"><div class="time">${safe(m.datetime)}</div><div class="row">${isPat ? '' : avatarMarkup}<div class="bubble"><div class="sender">${isPat ? '' : safe(m.name || (m.isSender ? '我' : '联系人'))}</div>${media}${audio}${quote}<div class="content">${safe(text || (!media && !audio && !quote ? `[${m.type}]` : ''))}</div>${mediaStatus}</div></div></article>`
    })
    .join('')
-  return `<!doctype html><html lang="zh-CN"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><title>${safe(name)} - 聊天记录</title><style>${exportStyles}</style></head><body><main class="page"><header class="toolbar"><div><span class="title">${safe(name)}</span><span class="meta">${messages.length.toLocaleString()} 条消息</span></div><div class="controls"><input id="query" type="search" placeholder="搜索消息..."><input id="point" type="datetime-local"><button id="jump">跳转</button><span class="count" id="count"></span></div></header><section class="scroll" id="messages">${body}</section></main><div class="lightbox" id="lightbox"><img id="lightbox-image" alt="预览"></div><script>(()=>{const all=[...document.querySelectorAll('.message')],q=document.querySelector('#query'),d=document.querySelector('#point'),c=document.querySelector('#count'),box=document.querySelector('#lightbox'),preview=document.querySelector('#lightbox-image');let zoom=1;const updateZoom=()=>preview.style.setProperty('--zoom',zoom);const update=()=>{const term=q.value.trim().toLowerCase(),at=d.value?new Date(d.value).getTime()/1000:0;let n=0;all.forEach(x=>{const ok=(!term||x.dataset.search.includes(term))&&(!at||Number(x.dataset.time)>=at);x.classList.toggle('hidden',!ok);if(ok)n++});c.textContent='共 '+n+' 条'};q.addEventListener('input',update);d.addEventListener('change',update);document.querySelector('#jump').onclick=()=>{const at=d.value?new Date(d.value).getTime()/1000:0;all.find(x=>Number(x.dataset.time)>=at)?.scrollIntoView({behavior:'smooth',block:'center'})};document.querySelectorAll('.media-image').forEach(image=>image.addEventListener('click',()=>{if(image.tagName==='IMG'){preview.src=image.src;zoom=1;updateZoom();box.classList.add('open')}}));preview.addEventListener('wheel',event=>{event.preventDefault();zoom=Math.min(5,Math.max(.5,zoom+(event.deltaY<0?.2:-.2)));updateZoom()},{passive:false});preview.addEventListener('dblclick',()=>{zoom=1;updateZoom()});box.addEventListener('click',event=>{if(event.target===box)box.classList.remove('open')});update()})()</script></body></html>`
+  return `<!doctype html><html lang="zh-CN"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><title>${safe(name)} - 聊天记录</title><style>${exportStyles}</style></head><body><main class="page"><header class="toolbar"><div><span class="title">${safe(name)}</span><span class="meta">${messages.length.toLocaleString()} 条消息</span></div><div class="controls"><input id="query" type="search" placeholder="搜索消息..."><input id="point" type="datetime-local"><button id="jump">跳转</button><span class="count" id="count"></span></div></header><section class="scroll" id="messages">${body}</section></main><div class="lightbox" id="lightbox"><button class="lightbox-close" id="lightbox-close" type="button" aria-label="关闭图片预览">×</button><img id="lightbox-image" alt="预览"></div><script>(()=>{const all=[...document.querySelectorAll('.message')],q=document.querySelector('#query'),d=document.querySelector('#point'),c=document.querySelector('#count'),box=document.querySelector('#lightbox'),preview=document.querySelector('#lightbox-image'),closeButton=document.querySelector('#lightbox-close');let zoom=1;const updateZoom=()=>preview.style.setProperty('--zoom',zoom);const closeLightbox=()=>{box.classList.remove('open');zoom=1;updateZoom()};const update=()=>{const term=q.value.trim().toLowerCase(),at=d.value?new Date(d.value).getTime()/1000:0;let n=0;all.forEach(x=>{const ok=(!term||x.dataset.search.includes(term))&&(!at||Number(x.dataset.time)>=at);x.classList.toggle('hidden',!ok);if(ok)n++});c.textContent='共 '+n+' 条'};q.addEventListener('input',update);d.addEventListener('change',update);document.querySelector('#jump').onclick=()=>{const at=d.value?new Date(d.value).getTime()/1000:0;all.find(x=>Number(x.dataset.time)>=at)?.scrollIntoView({behavior:'smooth',block:'center'})};document.querySelectorAll('.media-image').forEach(image=>image.addEventListener('click',()=>{if(image.tagName==='IMG'){preview.src=image.src;zoom=1;updateZoom();box.classList.add('open')}}));preview.addEventListener('wheel',event=>{event.preventDefault();zoom=Math.min(5,Math.max(.5,zoom+(event.deltaY<0?.2:-.2)));updateZoom()},{passive:false});preview.addEventListener('dblclick',()=>{zoom=1;updateZoom()});box.addEventListener('click',event=>{if(event.target===box)closeLightbox()});closeButton.addEventListener('click',closeLightbox);document.addEventListener('keydown',event=>{if(event.key==='Escape')closeLightbox()});update()})()</script></body></html>`
 }
@@ -16,6 +16,7 @@ import { ImageDecryptService } from './image-decrypt-service'
 import { ImageKeyConfigService } from './services/image-key-config-service'
 import { VideoAssetService } from './video-asset-service'
 import { StickerService } from './sticker-service'
+import { getImageExportAttempts } from '../shared/export-media'

 const jobs = new Set<string>()
 const safeFilePart = (value: string): string =>
@@ -26,6 +27,10 @@ const exportStamp = (): string => {
  return `${date.getFullYear()}${pad(date.getMonth() + 1)}${pad(date.getDate())}_${pad(date.getHours())}${pad(date.getMinutes())}${pad(date.getSeconds())}`
 }
 const imageKeys = new ImageKeyConfigService()
+
+const keepMediaError = (request: ExportRequest, message: Message, error: string): void => {
+  if (request.keepMissing !== false) message.exportMediaError = error
+}
 function decodeDataUrl(data: string): { extension: string; buffer: Buffer } | null {
  const match = /^data:([^;]+);base64,(.+)$/s.exec(data)
  if (!match) return null
@@ -105,11 +110,20 @@ function render(format: ExportRequest['format'], messages: Message[], name: stri
  if (format === 'json')
    return JSON.stringify({ name, exportedAt: new Date().toISOString(), messages }, null, 2)
  if (format === 'markdown')
-    return `# ${name}\n\n${messages.map((m) => `**${m.name || (m.isSender ? '我' : '联系人')}** · ${m.datetime}\n\n${m.content || `[${m.type}]`}\n`).join('\n')}`
+    return `# ${name}\n\n${messages.map((m) => `**${m.name || (m.isSender ? '我' : '联系人')}** · ${m.datetime}\n\n${m.content || `[${m.type}]`}${m.exportMediaUrl || m.voiceDataUrl || m.exportMediaError ? `\n\n媒体：${m.exportMediaUrl || m.voiceDataUrl || m.exportMediaError}` : ''}\n`).join('\n')}`
  return [
-    '时间,发送者,类型,内容',
+    '时间,发送者,类型,内容,媒体路径,媒体状态',
    ...messages.map((m) =>
-      [m.datetime, m.name || (m.isSender ? '我' : '联系人'), m.type, m.content].map(csv).join(',')
+      [
+        m.datetime,
+        m.name || (m.isSender ? '我' : '联系人'),
+        m.type,
+        m.content,
+        m.exportMediaUrl || m.voiceDataUrl || '',
+        m.exportMediaError || ''
+      ]
+        .map(csv)
+        .join(',')
    )
  ].join('\n')
 }
@@ -126,9 +140,19 @@ export async function runExport(request: ExportRequest, win: BrowserWindow): Pro
      .listMessages(request.userMd5, request.startTime, request.endTime)
      .filter((m) => request.kinds.includes(kindOf(m)))
    for (const message of messages) {
+      message.exportMediaUrl = undefined
+      message.exportMediaType = undefined
+      message.exportMediaError = undefined
+      message.voiceDataUrl = undefined
      message.exportShowAvatar = request.includeAvatars !== false
      const mappedName = message.senderId ? request.nameMap?.[message.senderId] : undefined
      if (mappedName) message.name = mappedName
+      if (
+        request.format !== 'html' &&
+        ['image', 'video', 'voice', 'sticker'].includes(kindOf(message))
+      ) {
+        message.exportMediaError = '当前导出格式记录媒体状态，但不复制媒体文件'
+      }
    }
    send({ jobId: request.jobId, phase: 'reading', processed: 10, total: 100, percent: 10 })
    if (!jobs.has(request.jobId)) {
@@ -181,25 +205,46 @@ export async function runExport(request: ExportRequest, win: BrowserWindow): Pro
          : null
      if (voiceService) {
        for (const [index, message] of messages.entries()) {
-          if (
-            kindOf(message) !== 'voice' ||
-            !message.sessionId ||
-            !message.localId ||
-            !message.createTime
-          )
+          if (kindOf(message) !== 'voice') continue
+          if (!message.sessionId || message.localId == null || !message.createTime) {
+            keepMediaError(request, message, '语音标识不完整，无法定位本地语音')
            continue
+          }
+          try {
            const voice = await voiceService.resolveVoice(
              message.sessionId,
              message.localId,
              message.createTime,
              message.serverId
            )
-          if (!voice.success || !voice.data) continue
+            if (!voice.success || !voice.data) {
+              const detail = voice.error || '未知原因'
+              const reason = /未找到|不存在|获取语音数据失败/.test(detail)
+                ? `语音文件缺失：${detail}`
+                : /Silk|解码|数据为空/.test(detail)
+                  ? `语音解析失败：${detail}`
+                  : `语音格式不支持或读取失败：${detail}`
+              keepMediaError(request, message, reason)
+              continue
+            }
            const voiceName = `voice_${index + 1}_${message.localId}.wav`
            const audioBuffer = Buffer.from(voice.data, 'base64')
            await fs.writeFile(join(outputDir, 'voices', voiceName), audioBuffer)
            message.voiceDataUrl = `voices/${voiceName}`
            message.voiceDuration = Math.max(1, Math.round(audioBuffer.length / (24000 * 2)))
+          } catch (error) {
+            keepMediaError(
+              request,
+              message,
+              `语音文件写入失败：${error instanceof Error ? error.message : String(error)}`
+            )
+          }
+        }
+      } else if (request.includeMedia) {
+        for (const message of messages) {
+          if (kindOf(message) === 'voice') {
+            keepMediaError(request, message, '数据库未连接，无法读取本地语音')
+          }
        }
      }
      for (const [index, message] of messages.entries()) {
@@ -228,35 +273,79 @@ export async function runExport(request: ExportRequest, win: BrowserWindow): Pro
          })
          continue
        }
-        if (message.contentData.type === 'image' && imageService) {
+        if (message.contentData.type === 'image') {
+          if (!imageService) {
+            keepMediaError(request, message, '未配置图片解密密钥，无法导出图片')
+          } else {
+            let fileFound = false
+            let decryptedImage: { data: string; filePath: string } | null = null
+            let usedFallback = false
+            for (const attempt of getImageExportAttempts(request)) {
              const file = imageService.findImageFile(
                message.contentData.md5,
                message.contentData.datName,
-            { allowThumbnail: true }
+                {
+                  allowThumbnail: attempt.allowThumbnail,
+                  preferThumbnail: attempt.preferThumbnail,
+                  sessionId: message.sessionId
+                }
              )
-          const decrypted = file ? imageService.decryptImageToBase64WithFallback(file, true) : null
-          const decoded = decrypted ? decodeDataUrl(decrypted.data) : null
+              if (!file) continue
+              fileFound = true
+              const decrypted = imageService.decryptImageToBase64WithFallback(
+                file,
+                attempt.allowThumbnail
+              )
+              if (!decrypted) continue
+              decryptedImage = decrypted
+              usedFallback = attempt.fallback || imageService.isThumbnailFile(decrypted.filePath)
+              break
+            }
+            const decoded = decryptedImage ? decodeDataUrl(decryptedImage.data) : null
            if (decoded) {
              const name = `image_${index + 1}.${decoded.extension}`
              await fs.writeFile(join(outputDir, 'media', name), decoded.buffer)
              message.exportMediaUrl = `media/${name}`
              message.exportMediaType = 'image'
+              if (usedFallback) {
+                keepMediaError(request, message, '原图不可用，已降级使用缩略图')
              }
-        } else if (message.contentData.type === 'video' && videoService) {
+            } else if (!fileFound) {
+              keepMediaError(
+                request,
+                message,
+                request.fallbackThumbnail === false
+                  ? '原图文件缺失，未启用缩略图降级'
+                  : '原图和缩略图文件均缺失'
+              )
+            } else {
+              keepMediaError(request, message, '图片解析失败或当前格式不支持')
+            }
+          }
+        } else if (message.contentData.type === 'video') {
          const hashes = [
            message.contentData.md5,
            message.contentData.newMd5,
            message.contentData.rawMd5
          ].filter((value): value is string => Boolean(value))
+          if (!videoService) {
+            keepMediaError(request, message, '数据库未连接，无法定位本地视频')
+          } else if (hashes.length === 0) {
+            keepMediaError(request, message, '视频标识不完整，无法定位本地视频')
+          } else {
            const resolved = videoService.resolve(hashes)
-          const token = resolved.url?.split('/').pop()
-          const source = token ? videoService.pathForToken(token) : undefined
-          if (source) {
+            const source = resolved.url ? videoService.pathForUrl(resolved.url) : undefined
+            if (!resolved.success || !source) {
+              keepMediaError(request, message, resolved.error || '视频文件缺失或已移动')
+            } else if (extname(source).toLowerCase() !== '.mp4') {
+              keepMediaError(request, message, '视频格式不支持，仅支持本地 MP4 文件')
+            } else {
              const name = `video_${index + 1}.mp4`
              await fs.copyFile(source, join(outputDir, 'media', name))
              message.exportMediaUrl = `media/${name}`
              message.exportMediaType = 'video'
            }
+          }
        } else if (message.contentData.type === 'sticker' && stickerService) {
          const stickerSource = message.contentData.url || message.contentData.thumbUrl
          const result = await stickerService.resolveSticker(stickerSource, message.contentData.md5)
@@ -270,6 +359,8 @@ export async function runExport(request: ExportRequest, win: BrowserWindow): Pro
            await fs.writeFile(join(outputDir, 'media', name), decoded.buffer)
            message.exportMediaUrl = `media/${name}`
            message.exportMediaType = 'sticker'
+          } else {
+            keepMediaError(request, message, result.error || '表情资源缺失或下载失败')
          }
        }
        send({
@@ -58,13 +58,25 @@ import * as chat from './services/chat-service'
 import { apiServer } from './http-server'
 import { skillResourceService } from './services/skill-resource-service'
 import { testLocalApiRequest } from './services/local-api-test-service'
-import { isWindowsWechatRunning } from './services/wechat-process-status'
+import { isWechatRunning } from './services/wechat-process-status'
 import {
  inspectImageDecryptionStatus,
  testImageDecryption
 } from './services/image-decryption-status-service'
 import type { SaveImageKeyRequest, TestImageDecryptionRequest } from '../shared/image-decryption'
-import { loadSettings, saveSettings, getSettingsPath, AppSettings } from './services/settings-store'
+import {
+  loadSettings,
+  saveSettings,
+  getSettingsPath,
+  AppSettings,
+  validateDbRoot
+} from './services/settings-store'
+import {
+  detectDataStructureVersion,
+  detectWechatVersion,
+  getOsVersionLabel
+} from './services/connection-diagnostics'
+import { buildSafeDiagnosticSummary } from '../shared/connection-diagnostics'
 import {
  flushBootstrapCacheWritesSync,
  getBootstrapCache,
@@ -88,6 +100,7 @@ import { configureRecallArchive, RecallArchiveMonitor } from './services/recall-
 import { VideoAssetService } from './video-asset-service'
 import { cancelExport, revealExport, runExport } from './export-service'
 import type { ExportRequest } from '../shared/export'
+import { discoverAccounts } from './services/account-discovery'

 // electron-vite can close the child's stdout/stderr after spawning Electron.
 // Plain console.error then throws EPIPE on a closed pipe and crashes the IPC
@@ -479,7 +492,7 @@ app.whenReady().then(async () => {
    return clearCache(scope)
  })

-  ipcMain.handle('db:init', async (_, key: string) => {
+  ipcMain.handle('db:init', async (_, key: string, accountRoot?: string) => {
    if (dbInitInFlight) return dbInitInFlight

    dbInitInFlight = (async () => {
@@ -489,17 +502,35 @@ app.whenReady().then(async () => {
        const trimmedKey = String(key || '').trim()
        console.log(`db:init build=${BUILD_MARK} keyLength=${trimmedKey.length}`)
        const settings = loadSettings()
+        const selectedRoot = String(accountRoot || settings.dbRoot || '').trim()
+        const rootValidation = validateDbRoot(selectedRoot)
+        if (!rootValidation.valid) {
+          return {
+            success: false,
+            code: 'ROOT_UNAVAILABLE',
+            error: rootValidation.error,
+            monitoring: false
+          }
+        }
+        if (!existsSync(join(selectedRoot, 'db_storage'))) {
+          return {
+            success: false,
+            code: 'ACCOUNT_SELECTION_REQUIRED',
+            error: '请先明确选择一个微信账号',
+            monitoring: false
+          }
+        }
        if (
          chat.isReady() &&
          chat.getCurrentKey().replace(/^0x/i, '').trim() === trimmedKey.replace(/^0x/i, '') &&
-          (!settings.dbRoot || chat.getCurrentAccountRoot() === settings.dbRoot)
+          chat.getCurrentAccountRoot() === selectedRoot
        ) {
          console.log('[WCDB4] db:init reuse current connection')
          return { success: true, monitoring: true }
        }
-        const nextWechatDb = await WechatDb.create(key, settings.dbRoot)
+        const nextWechatDb = await WechatDb.create(key, selectedRoot)
        const resolvedRoot = nextWechatDb.getWcdb4Client().getAccountRoot()
-        if (resolvedRoot && resolvedRoot !== settings.dbRoot) {
+        if (resolvedRoot) {
          // 同步更新 imageKeyRoot，避免自动获取图片密钥时扫描到错误目录
          saveSettings({
            ...settings,
@@ -543,19 +574,43 @@ app.whenReady().then(async () => {
    return dbInitInFlight
  })

-  ipcMain.handle('key:getSavedDbKey', async () => databaseKeyStore.load())
+  ipcMain.handle('accounts:discover', (_, inputPath: string) =>
+    discoverAccounts(inputPath, databaseKeyStore, chat.getCurrentAccountRoot())
+  )
+
+  ipcMain.handle('key:getSavedDbKey', async (_, accountRoot: string) => {
+    const selectedRoot = String(accountRoot || '').trim()
+    const scoped = await databaseKeyStore.load(selectedRoot)
+    if (scoped.saved || !selectedRoot) return scoped
+    const legacy = await databaseKeyStore.loadLegacy()
+    if (!legacy.success || !legacy.key) return scoped
+    const validation = await chat.testConnection(legacy.key, selectedRoot)
+    if (!validation.success) return scoped
+    const migrated = await databaseKeyStore.save(selectedRoot, legacy.key)
+    if (migrated.success) await databaseKeyStore.clearLegacy()
+    return migrated
+  })

  ipcMain.handle('key:getEnvironment', async () => {
-    const storage = await databaseKeyStore.getStatus()
+    const storage = await databaseKeyStore.getStatus(
+      chat.getCurrentAccountRoot() || loadSettings().dbRoot
+    )
    const self = chat.getSelfAccountInfo()
-    return {
+    const settings = loadSettings()
+    const environment = {
      platform: process.platform,
+      osVersion: getOsVersionLabel(),
+      appVersion: `v${app.getVersion()}`,
+      wechatVersion: await detectWechatVersion(),
+      dataStructureVersion: detectDataStructureVersion(settings.dbRoot),
+      dataDirectoryDetected: validateDbRoot(settings.dbRoot).valid,
      autoDetectSupported: process.platform === 'win32',
-      wechatRunning: await isWindowsWechatRunning(),
+      wechatRunning: await isWechatRunning(),
      accountIdentified: Boolean(self?.wxid),
      dbConnected: chat.isReady(),
      encryptionAvailable: storage.encryptionAvailable
    }
+    return { ...environment, diagnosticSummary: buildSafeDiagnosticSummary(environment) }
  })

  ipcMain.handle('key:readClipboardDbKey', () => {
@@ -566,18 +621,22 @@ app.whenReady().then(async () => {
    }
  })

-  ipcMain.handle('key:pasteAndSaveDbKey', async () => {
+  ipcMain.handle('key:pasteAndSaveDbKey', async (_, accountRoot: string) => {
    const clipboardKey = clipboard.readText().trim()
-    return databaseKeyStore.save(clipboardKey)
+    return databaseKeyStore.save(String(accountRoot || ''), clipboardKey)
  })

-  ipcMain.handle('key:saveDbKey', async (_, key: string) =>
-    databaseKeyStore.save(String(key || ''))
+  ipcMain.handle('key:saveDbKey', async (_, accountRoot: string, key: string) =>
+    databaseKeyStore.save(String(accountRoot || ''), String(key || ''))
  )

-  ipcMain.handle('key:clearSavedDbKey', async () => databaseKeyStore.clear())
+  ipcMain.handle('key:clearSavedDbKey', async (_, accountRoot: string) =>
+    databaseKeyStore.clear(String(accountRoot || ''))
+  )

-  ipcMain.handle('key:autoGetDbKey', async (event, options?: { save?: boolean }) => {
+  ipcMain.handle(
+    'key:autoGetDbKey',
+    async (event, accountRoot: string, options?: { save?: boolean }) => {
      const onStatus = (message: string): void => {
        if (!event.sender.isDestroyed()) event.sender.send('key:dbKeyStatus', { message })
      }
@@ -587,15 +646,22 @@ app.whenReady().then(async () => {
          : await keyServiceMac.autoGetDbKey(onStatus)
      if (!result.success || !result.key) return result

+      const selectedRoot = String(accountRoot || '').trim()
+      if (!selectedRoot) return { success: false, error: '请先选择微信账号' }
+      const validation = await chat.testConnection(result.key, selectedRoot)
+      if (!validation.success) {
+        return { ...result, success: false, key: undefined, error: '获取到的密钥不属于所选账号' }
+      }
      if (options?.save === false) return result

-    const saved = await databaseKeyStore.save(result.key)
+      const saved = await databaseKeyStore.save(selectedRoot, result.key)
      return {
        ...result,
        saved: saved.success,
        warning: saved.success ? undefined : saved.error
      }
-  })
+    }
+  )

  ipcMain.handle('key:autoGetImageKey', async (event, options?: { save?: boolean }) => {
    const settings = loadSettings()
@@ -0,0 +1,58 @@
+import crypto from 'crypto'
+import fs from 'fs-extra'
+import path from 'path'
+import type { AccountDiscoveryResult, WechatAccountCandidate } from '../../shared/database-key'
+import { DatabaseKeyStore } from '../database-key-store'
+import { getBootstrapCache } from './bootstrap-cache'
+import { validateDbRoot } from './settings-store'
+
+function accountId(accountRoot: string): string {
+  return crypto.createHash('sha256').update(path.resolve(accountRoot).toLowerCase()).digest('hex')
+}
+
+export async function discoverAccounts(
+  inputPath: string,
+  keyStore: DatabaseKeyStore,
+  currentAccountRoot?: string
+): Promise<AccountDiscoveryResult> {
+  const validation = validateDbRoot(inputPath)
+  if (!validation.valid) return { success: false, accounts: [], error: validation.error }
+
+  const normalizedInput = path.resolve(inputPath)
+  const isAccount = await fs.pathExists(path.join(normalizedInput, 'db_storage'))
+  const roots = isAccount
+    ? [normalizedInput]
+    : (await fs.readdir(normalizedInput, { withFileTypes: true }))
+        .filter((entry) => entry.isDirectory())
+        .map((entry) => path.join(normalizedInput, entry.name))
+        .filter((candidate) => fs.existsSync(path.join(candidate, 'db_storage')))
+
+  const accounts: WechatAccountCandidate[] = await Promise.all(
+    roots.map(async (accountRoot) => {
+      const cached = getBootstrapCache(accountRoot)?.self
+      return {
+        id: accountId(accountRoot),
+        accountRoot,
+        directoryName: path.basename(accountRoot),
+        wxid: cached?.wxid,
+        nickname: cached?.nickname,
+        avatar: cached?.avatar,
+        hasSavedDbKey: (await keyStore.getStatus(accountRoot)).saved,
+        loginStatus: currentAccountRoot
+          ? path.resolve(currentAccountRoot).toLowerCase() ===
+            path.resolve(accountRoot).toLowerCase()
+            ? 'current'
+            : 'other'
+          : 'unknown',
+        selectedByInput: isAccount
+      }
+    })
+  )
+
+  return {
+    success: true,
+    inputKind: isAccount ? 'account' : 'root',
+    accounts,
+    preselectedAccountId: isAccount ? accounts[0]?.id : undefined
+  }
+}
@@ -0,0 +1,69 @@
+import { execFile } from 'child_process'
+import fs from 'fs-extra'
+import os from 'os'
+import path from 'path'
+import { promisify } from 'util'
+import { isUsableDbRoot } from './settings-store'
+
+const execFileAsync = promisify(execFile)
+
+const platformLabel = (): string => {
+  if (process.platform === 'win32') return `Windows ${os.release()} (${process.arch})`
+  if (process.platform === 'darwin') return `macOS ${os.release()} (${process.arch})`
+  return `${process.platform} ${os.release()} (${process.arch})`
+}
+
+async function detectWindowsWechatVersion(): Promise<string> {
+  const script = [
+    '$process = Get-Process Weixin,WeChat -ErrorAction SilentlyContinue | Where-Object Path | Select-Object -First 1',
+    '$candidate = if ($process) { $process.Path } else {',
+    "  @($env:ProgramFiles, ${env:ProgramFiles(x86)}) | Where-Object { $_ } | ForEach-Object { Join-Path $_ 'Tencent\\WeChat\\WeChat.exe' } | Where-Object { Test-Path $_ } | Select-Object -First 1",
+    '}',
+    'if ($candidate) { (Get-Item -LiteralPath $candidate).VersionInfo.ProductVersion }'
+  ].join('; ')
+  try {
+    const { stdout } = await execFileAsync(
+      'powershell.exe',
+      ['-NoProfile', '-NonInteractive', '-Command', script],
+      { timeout: 3000, windowsHide: true }
+    )
+    return stdout.trim() || '未检测到'
+  } catch {
+    return '未检测到'
+  }
+}
+
+async function detectMacWechatVersion(): Promise<string> {
+  const candidates = [
+    '/Applications/WeChat.app/Contents/Info',
+    path.join(os.homedir(), 'Applications/WeChat.app/Contents/Info')
+  ]
+  for (const candidate of candidates) {
+    if (!fs.existsSync(`${candidate}.plist`)) continue
+    try {
+      const { stdout } = await execFileAsync(
+        '/usr/bin/defaults',
+        ['read', candidate, 'CFBundleShortVersionString'],
+        { timeout: 3000 }
+      )
+      if (stdout.trim()) return stdout.trim()
+    } catch {
+      // Continue to the next known installation location.
+    }
+  }
+  return '未检测到'
+}
+
+export async function detectWechatVersion(): Promise<string> {
+  if (process.platform === 'win32') return detectWindowsWechatVersion()
+  if (process.platform === 'darwin') return detectMacWechatVersion()
+  return '未检测到'
+}
+
+export function detectDataStructureVersion(dbRoot: string): string {
+  return isUsableDbRoot(dbRoot) ? '微信 4.x（WCDB）' : '未检测到'
+}
+
+export function getOsVersionLabel(): string {
+  return platformLabel()
+}
@@ -86,7 +86,7 @@ function unique(values: string[]): string[] {
  return Array.from(new Set(values))
 }

-function isUsableDbRoot(candidate?: string): boolean {
+export function isUsableDbRoot(candidate?: string): boolean {
  if (!candidate || !fs.existsSync(candidate)) return false
  if (fs.existsSync(path.join(candidate, 'db_storage'))) return true
  try {
@@ -98,6 +98,21 @@ function isUsableDbRoot(candidate?: string): boolean {
  }
 }

+export function validateDbRoot(candidate?: string): { valid: boolean; error?: string } {
+  const root = String(candidate || '').trim()
+  if (!root) return { valid: false, error: '微信数据目录为空，请重新选择目录' }
+  if (!fs.existsSync(root)) {
+    return { valid: false, error: '微信数据目录不存在，请检查路径或重新选择目录' }
+  }
+  if (!isUsableDbRoot(root)) {
+    return {
+      valid: false,
+      error: '所选目录中未找到微信 4.x 数据库（db_storage），请选择 xwechat_files 或账号目录'
+    }
+  }
+  return { valid: true }
+}
+
 const defaultDbRoot = getDefaultDbRoot()

 const DEFAULT_SETTINGS: AppSettings = {
@@ -938,9 +938,27 @@ export class Wcdb4Client {
  ): Promise<Wcdb4Message[]> {
    const startedAt = Date.now()
    const maxRows = this.normalizeMessageLimit(options.limit)
-    const messages = await this.getMessagesByCursorAsync(username, startTime, endTime, maxRows)
+    let cursorMessages: Wcdb4Message[] = []
+    try {
+      cursorMessages = await this.getMessagesByCursorAsync(username, startTime, endTime, maxRows)
+    } catch (error) {
+      console.warn(`[WCDB4] async cursor messages failed username=${username}:`, error)
+    }
+
+    if (endTime && (!this.wcdbGetMessageTableStats || !this.wcdbExecQuery)) {
+      throw new Error('当前数据服务无法检查历史消息分片，请更新应用或核对微信数据版本')
+    }
+
+    // Older pages may live in message shards that the native cursor does not
+    // enumerate. A bounded query must inspect all matching stores so history
+    // cannot silently stop at a shard boundary.
+    let tableMessages: Wcdb4Message[] = []
+    if (endTime || cursorMessages.length === 0) {
+      tableMessages = await this.getMessagesByTableScanAsync(username, startTime, endTime, maxRows)
+    }
+    const messages = this.mergeMessageRows(cursorMessages, tableMessages, maxRows)
    console.log(
-      `[WCDB4] getMessages async username=${username} rows=${messages.length} cost=${Date.now() - startedAt}ms`
+      `[WCDB4] getMessages async username=${username} rows=${messages.length} cursor=${cursorMessages.length} tables=${tableMessages.length} cost=${Date.now() - startedAt}ms`
    )
    return messages
  }
@@ -998,6 +1016,71 @@ export class Wcdb4Client {
    return this.finalizeMessages(username, allRows, startTime, endTime, limit)
  }

+  private async getMessagesByTableScanAsync(
+    username: string,
+    startTime?: number,
+    endTime?: number,
+    limit?: number
+  ): Promise<Wcdb4Message[]> {
+    if (!this.wcdbGetMessageTableStats || !this.wcdbExecQuery) return []
+
+    let tables: Wcdb4MessageStore[] = []
+    try {
+      const rows = await this.callJsonAsync<Record<string, unknown>[]>(
+        this.wcdbGetMessageTableStats as unknown as KoffiAsyncFunction,
+        username
+      )
+      tables = (Array.isArray(rows) ? rows : [])
+        .map((row) => ({
+          tableName: this.pickString(row, ['table_name', 'tableName', 'name']),
+          dbPath: this.pickString(row, ['db_path', 'dbPath', 'path'])
+        }))
+        .filter((row) => row.tableName && row.dbPath)
+    } catch (error) {
+      console.warn(`[WCDB4] async message table stats failed username=${username}:`, error)
+      throw new Error(
+        `无法读取历史消息分片信息：${error instanceof Error ? error.message : String(error)}`
+      )
+    }
+
+    const begin = this.normalizeTimestamp(startTime || 0)
+    const end = this.normalizeTimestamp(endTime || 0)
+    const where = [
+      begin > 0 ? `"create_time" >= ${begin}` : '',
+      end > 0 ? `"create_time" <= ${end}` : ''
+    ].filter(Boolean)
+    const whereSql = where.length ? ` WHERE ${where.join(' AND ')}` : ''
+    const rowLimit = limit || 5000
+    const order = limit ? 'DESC' : 'ASC'
+
+    const allRows: Record<string, unknown>[] = []
+    let successfulTables = 0
+    for (const table of tables) {
+      try {
+        const sql = `SELECT * FROM ${this.quoteSqlIdentifier(table.tableName)}${whereSql} ORDER BY "create_time" ${order} LIMIT ${rowLimit}`
+        const rows = await this.callJsonAsync<Record<string, unknown>[]>(
+          this.wcdbExecQuery as unknown as KoffiAsyncFunction,
+          'message',
+          table.dbPath,
+          sql
+        )
+        successfulTables += 1
+        if (Array.isArray(rows)) allRows.push(...rows)
+      } catch (error) {
+        console.warn(
+          `[WCDB4] async message table scan failed username=${username} db=${table.dbPath} table=${table.tableName}:`,
+          error
+        )
+      }
+    }
+
+    if (tables.length > 0 && successfulTables === 0) {
+      throw new Error('历史消息分片均读取失败，请检查数据目录或微信数据版本')
+    }
+
+    return this.finalizeMessages(username, allRows, startTime, endTime, limit)
+  }
+
  installRecallJournal(usernames: string[]): { installed: number; failed: number } {
    const stores = new Map<string, Wcdb4MessageStore>()
    for (const username of this.uniq(usernames)) {
@@ -11,7 +11,8 @@ import {
 import type {
  DatabaseKeyEnvironment,
  DatabaseKeyStorageResult,
-  DatabaseKeyValidationResult
+  DatabaseKeyValidationResult,
+  AccountDiscoveryResult
 } from '../shared/database-key'
 import type {
  ImageDecoderSelectionResult,
@@ -115,8 +116,10 @@ declare global {
      getCacheSummary: () => Promise<CacheSummary>
      clearCache: (scope: 'bootstrap' | 'electron' | 'all') => Promise<CacheSummary>
      initDb: (
-        key: string
+        key: string,
+        accountRoot: string
      ) => Promise<boolean | { success: boolean; error?: string; monitoring?: boolean }>
+      discoverAccounts: (inputPath: string) => Promise<AccountDiscoveryResult>
      getBootstrapCache: () => Promise<{
        self?: { wxid: string; nickname: string; avatar?: string; accountRoot: string }
        contacts: Contact[]
@@ -239,14 +242,17 @@ declare global {
      ) => Promise<SaveGeneratedReportResult>
      deleteGeneratedReport: (reportId: string) => Promise<DeleteGeneratedReportResult>
      revealGroupReport: (filePath: string) => Promise<{ success: boolean; error?: string }>
-      getSavedDbKey: () => Promise<DatabaseKeyStorageResult>
+      getSavedDbKey: (accountRoot: string) => Promise<DatabaseKeyStorageResult>
      getDatabaseKeyEnvironment: () => Promise<DatabaseKeyEnvironment>
      readDatabaseKeyClipboard: () => Promise<{
        success: boolean
        value?: string
        error?: string
      }>
-      autoGetDbKey: (options?: { save?: boolean }) => Promise<{
+      autoGetDbKey: (
+        accountRoot: string,
+        options?: { save?: boolean }
+      ) => Promise<{
        success: boolean
        key?: string
        error?: string
@@ -290,9 +296,11 @@ declare global {
        request: TestImageDecryptionRequest
      ) => Promise<ImageDecryptionTestResult>
      clearImageKeyConfig: () => Promise<{ success: boolean; error?: string }>
-      pasteAndSaveDbKey: () => Promise<{ success: boolean; key?: string; error?: string }>
-      saveDbKey: (key: string) => Promise<DatabaseKeyStorageResult>
-      clearSavedDbKey: () => Promise<{ success: boolean; error?: string }>
+      pasteAndSaveDbKey: (
+        accountRoot: string
+      ) => Promise<{ success: boolean; key?: string; error?: string }>
+      saveDbKey: (accountRoot: string, key: string) => Promise<DatabaseKeyStorageResult>
+      clearSavedDbKey: (accountRoot: string) => Promise<{ success: boolean; error?: string }>
      onWcdbChange: (callback: (payload: { type: string; json: string }) => void) => () => void
      onDbKeyStatus: (callback: (payload: { message: string }) => void) => () => void
      onImageKeyStatus: (callback: (payload: { message: string }) => void) => () => void
@@ -21,6 +21,7 @@ import type { AppUpdateState } from '../shared/app-update'
 import type { CacheSummary } from '../shared/cache'
 import type { ExportRequest, ExportJobProgress } from '../shared/export'
 import type { ImageDecoderSelectionResult, ImageDecoderStatus } from '../shared/image-decryption'
+import type { AccountDiscoveryResult } from '../shared/database-key'

 // 渲染器的自定义 API
 const api = {
@@ -40,7 +41,9 @@ const api = {
  getCacheSummary: (): Promise<CacheSummary> => ipcRenderer.invoke('cache:getSummary'),
  clearCache: (scope: 'bootstrap' | 'electron' | 'all'): Promise<CacheSummary> =>
    ipcRenderer.invoke('cache:clear', scope),
-  initDb: (key: string) => ipcRenderer.invoke('db:init', key),
+  initDb: (key: string, accountRoot: string) => ipcRenderer.invoke('db:init', key, accountRoot),
+  discoverAccounts: (inputPath: string): Promise<AccountDiscoveryResult> =>
+    ipcRenderer.invoke('accounts:discover', inputPath),
  getBootstrapCache: () => ipcRenderer.invoke('db:getBootstrapCache'),
  getStartupCache: () => ipcRenderer.invoke('db:getStartupCache'),
  getContacts: (filter?: string) => ipcRenderer.invoke('db:getContacts', filter),
@@ -98,10 +101,11 @@ const api = {
  deleteGeneratedReport: (reportId: string) =>
    ipcRenderer.invoke('report:deleteGenerated', reportId),
  revealGroupReport: (filePath: string) => ipcRenderer.invoke('report:reveal', filePath),
-  getSavedDbKey: () => ipcRenderer.invoke('key:getSavedDbKey'),
+  getSavedDbKey: (accountRoot: string) => ipcRenderer.invoke('key:getSavedDbKey', accountRoot),
  getDatabaseKeyEnvironment: () => ipcRenderer.invoke('key:getEnvironment'),
  readDatabaseKeyClipboard: () => ipcRenderer.invoke('key:readClipboardDbKey'),
-  autoGetDbKey: (options?: { save?: boolean }) => ipcRenderer.invoke('key:autoGetDbKey', options),
+  autoGetDbKey: (accountRoot: string, options?: { save?: boolean }) =>
+    ipcRenderer.invoke('key:autoGetDbKey', accountRoot, options),
  autoGetImageKey: (options?: { save?: boolean }) =>
    ipcRenderer.invoke('key:autoGetImageKey', options),
  getImageKeyConfig: () => ipcRenderer.invoke('image:getConfig'),
@@ -115,9 +119,11 @@ const api = {
  saveImageKeyConfig: (request) => ipcRenderer.invoke('image:saveConfig', request),
  testImageDecryption: (request) => ipcRenderer.invoke('image:testConfig', request),
  clearImageKeyConfig: () => ipcRenderer.invoke('image:clearConfig'),
-  pasteAndSaveDbKey: () => ipcRenderer.invoke('key:pasteAndSaveDbKey'),
-  saveDbKey: (key: string) => ipcRenderer.invoke('key:saveDbKey', key),
-  clearSavedDbKey: () => ipcRenderer.invoke('key:clearSavedDbKey'),
+  pasteAndSaveDbKey: (accountRoot: string) =>
+    ipcRenderer.invoke('key:pasteAndSaveDbKey', accountRoot),
+  saveDbKey: (accountRoot: string, key: string) =>
+    ipcRenderer.invoke('key:saveDbKey', accountRoot, key),
+  clearSavedDbKey: (accountRoot: string) => ipcRenderer.invoke('key:clearSavedDbKey', accountRoot),
  onWcdbChange: (callback: (payload: { type: string; json: string }) => void) => {
    const listener = (
      _event: Electron.IpcRendererEvent,
@@ -24,6 +24,7 @@ import { FirstUseWelcome } from './components/FirstUseWelcome'
 import { ExportWorkspace } from './components/export/ExportWorkspace'
 import { AISearchWorkspace } from './components/search/AISearchWorkspace'
 import type { ExportJobProgress, ExportRequest, ExportTaskRecord } from '../../shared/export'
+import type { DatabaseKeyEnvironment, WechatAccountCandidate } from '../../shared/database-key'
 import {
  getMessageIdentity,
  mergeMessagePages,
@@ -32,6 +33,23 @@ import {

 const SIDEBAR_MIN_WIDTH = 260
 const SIDEBAR_MAX_WIDTH = 380
+const DATABASE_CONNECT_TIMEOUT_MS = 30_000
+
+function withTimeout<T>(promise: Promise<T>, timeoutMs: number, message: string): Promise<T> {
+  return new Promise<T>((resolve, reject) => {
+    const timer = window.setTimeout(() => reject(new Error(message)), timeoutMs)
+    promise.then(
+      (value) => {
+        window.clearTimeout(timer)
+        resolve(value)
+      },
+      (error) => {
+        window.clearTimeout(timer)
+        reject(error)
+      }
+    )
+  })
+}

 function getDevelopmentDatabaseKey(): string {
  if (!import.meta.env.DEV) return ''
@@ -202,6 +220,7 @@ function App(): React.ReactElement {
  const [selectedContact, setSelectedContact] = useState<Contact | null>(null)
  const [messages, setMessages] = useState<Message[]>([])
  const [isMessagesLoading, setIsMessagesLoading] = useState(false)
+  const [messageHistoryStatus, setMessageHistoryStatus] = useState<'idle' | 'end' | 'error'>('idle')
  const [filteredContacts, setFilteredContacts] = useState<Contact[]>([])
  const [contentFilter, setContentFilter] = useState('')
  const [isFetchingDbKey, setIsFetchingDbKey] = useState(false)
@@ -209,10 +228,16 @@ function App(): React.ReactElement {
  const [dbKeyStatusKind, setDbKeyStatusKind] = useState<'normal' | 'success' | 'error'>('normal')
  const [showDbKey, setShowDbKey] = useState(false)
  const [dbRootInput, setDbRootInput] = useState('')
+  const [discoveredAccounts, setDiscoveredAccounts] = useState<WechatAccountCandidate[]>([])
+  const [selectedAccountId, setSelectedAccountId] = useState('')
+  const selectedAccount = discoveredAccounts.find((account) => account.id === selectedAccountId)
  const [showMacKeyFaq, setShowMacKeyFaq] = useState(false)
  const [databaseConnectionMode, setDatabaseConnectionMode] = useState<DatabaseConnectionMode>(
    getDevelopmentDatabaseKey() ? 'manual' : 'automatic'
  )
+  const [connectionGuideStep, setConnectionGuideStep] = useState<1 | 2 | 3 | 4 | 5 | 6>(1)
+  const [databaseEnvironment, setDatabaseEnvironment] = useState<DatabaseKeyEnvironment>()
+  const connectionOperationRef = React.useRef(0)
  const [activePage, setActivePage] = useState<AppPage>('archive')
  const [archiveJumpTime, setArchiveJumpTime] = useState<number | null>(null)
  const [settingsCategory, setSettingsCategory] = useState<SettingsCategoryId>('account-database')
@@ -278,6 +303,34 @@ function App(): React.ReactElement {
      })
    })
  }, [])
+
+  const refreshConnectionEnvironment = React.useCallback(async (): Promise<void> => {
+    const root = dbRootInput.trim()
+    try {
+      if (root) {
+        const discovery = await window.api.discoverAccounts(root)
+        if (!discovery.success) throw new Error(discovery.error || '账号目录识别失败')
+        setDiscoveredAccounts(discovery.accounts)
+        setSelectedAccountId(discovery.preselectedAccountId || '')
+      }
+      const environment = await window.api.getDatabaseKeyEnvironment()
+      setDatabaseEnvironment(environment)
+      setDbKeyStatus('环境检查已更新')
+      setDbKeyStatusKind('normal')
+    } catch (error) {
+      setDbKeyStatus(
+        error instanceof Error ? `环境检查失败：${error.message}` : '环境检查失败，请重试'
+      )
+      setDbKeyStatusKind('error')
+    }
+  }, [dbRootInput])
+
+  React.useEffect(() => {
+    void window.api
+      .getDatabaseKeyEnvironment()
+      .then(setDatabaseEnvironment)
+      .catch(() => undefined)
+  }, [])
  React.useEffect(() => {
    const loadAIConfig = async (): Promise<void> => {
      try {
@@ -533,13 +586,26 @@ function App(): React.ReactElement {
      if (active && settingsResult.settings.dbRoot) {
        setDbRootInput(settingsResult.settings.dbRoot)
      }
+      const discovery = settingsResult.settings.dbRoot
+        ? await window.api.discoverAccounts(settingsResult.settings.dbRoot)
+        : { success: false, accounts: [] }
+      if (active && discovery.success) {
+        setDiscoveredAccounts(discovery.accounts)
+        setSelectedAccountId(discovery.preselectedAccountId || '')
+      }
+      const startupAccountRoot = discovery.success
+        ? discovery.accounts.find((account) => account.id === discovery.preselectedAccountId)
+            ?.accountRoot
+        : undefined
      const autoLoginEnabled = settingsResult.settings.autoLogin
      // 开发环境允许使用 VITE_DB_KEY；生产安装包只能读取目标电脑自己的 safeStorage。
      const envKey = getDevelopmentDatabaseKey()
      // 生产环境以及未配置开发密钥时，读取上一次保存到 safeStorage 的密钥。
      let savedKey = ''
      if (!envKey) {
-        const result = await window.api.getSavedDbKey()
+        const result = startupAccountRoot
+          ? await window.api.getSavedDbKey(startupAccountRoot)
+          : { success: true, saved: false, encryptionAvailable: true }
        if (result.success && result.key) savedKey = result.key
      }
      const key = envKey || savedKey
@@ -570,7 +636,11 @@ function App(): React.ReactElement {
      try {
        const startupCacheReady = await loadStartupCache()
        setIsDatabaseConnecting(true)
-        const initPromise = window.api.initDb(key)
+        if (!startupAccountRoot) {
+          setBootState('login')
+          return
+        }
+        const initPromise = window.api.initDb(key, startupAccountRoot)
        if (startupCacheReady) {
          setIsAuthenticated(true)
          setIsDatabaseConnected(false)
@@ -655,13 +725,36 @@ function App(): React.ReactElement {
    void loadGeneratedReports()
  }, [isAuthenticated, loadGeneratedReports])

-  const handleLogin = async (keyInput?: string): Promise<void> => {
+  const handleLogin = async (keyInput?: string, accountRootInput?: string): Promise<void> => {
    const keyToUse = keyInput || dbKey
-    if (!keyToUse) return
-    setBootState('connecting')
+    let accountRoot = accountRootInput || selectedAccount?.accountRoot
+    if (!keyToUse || isDatabaseConnecting) return
+    if (!accountRoot) {
+      const discovery = await window.api.discoverAccounts(dbRootInput.trim())
+      if (!discovery.success) {
+        setDbKeyStatus(discovery.error || '微信数据目录不可用')
+        setDbKeyStatusKind('error')
+        return
+      }
+      if (!discovery.preselectedAccountId) {
+        setDiscoveredAccounts(discovery.accounts)
+        setDbKeyStatus('请选择要连接的微信账号')
+        setDbKeyStatusKind('error')
+        return
+      }
+      const account = discovery.accounts.find(
+        (candidate) => candidate.id === discovery.preselectedAccountId
+      )
+      if (!account) return
+      setDiscoveredAccounts(discovery.accounts)
+      setSelectedAccountId(account.id)
+      accountRoot = account.accountRoot
+    }
+    const operationId = ++connectionOperationRef.current
+    if (databaseConnectionMode === 'automatic') setConnectionGuideStep(6)
    setIsDatabaseConnecting(true)
    // 持久化用户手动指定的微信聊天文件路径，供 db:init 读取 settings.dbRoot
-    const trimmedRoot = dbRootInput.trim()
+    const trimmedRoot = accountRoot
    if (trimmedRoot) {
      try {
        await window.api.setSettings({ dbRoot: trimmedRoot })
@@ -682,7 +775,12 @@ function App(): React.ReactElement {
        detail: '正在打开 WCDB 数据库',
        percent: 15
      })
-      const result = await window.api.initDb(keyToUse)
+      const result = await withTimeout(
+        window.api.initDb(keyToUse, trimmedRoot),
+        DATABASE_CONNECT_TIMEOUT_MS,
+        '数据库连接超时，请检查数据目录后重试'
+      )
+      if (operationId !== connectionOperationRef.current) return
      const success = typeof result === 'boolean' ? result : result.success
      if (success) {
        setIsNativeMonitorActive(typeof result !== 'boolean' && result.monitoring === true)
@@ -693,8 +791,9 @@ function App(): React.ReactElement {
          percent: 25
        })
        const hasBootstrap = await loadBootstrapCache()
+        if (operationId !== connectionOperationRef.current) return
        // 持久化手动输入的密钥，供下次启动继续使用
-        void window.api.saveDbKey(keyToUse).catch(() => undefined)
+        void window.api.saveDbKey(trimmedRoot, keyToUse).catch(() => undefined)
        void window.api.getSettings().then((current) => {
          if (!current.settings.autoLoginPreferenceSet) {
            void window.api.setSettings({ autoLogin: true })
@@ -734,17 +833,23 @@ function App(): React.ReactElement {
        }, 500)
      } else {
        const error = typeof result === 'boolean' ? '' : result.error
+        setDbKeyStatus(error || '数据库连接失败，请检查密钥和数据目录后重试')
+        setDbKeyStatusKind('error')
+        if (databaseConnectionMode === 'automatic') setConnectionGuideStep(5)
        setBootState('login')
        setStartupProgress(null)
-        alert(`Failed to open database.${error ? `\n\n${error}` : '\nCheck your key.'}`)
      }
    } catch (error) {
      console.error(error)
+      setDbKeyStatus(
+        error instanceof Error ? `数据库连接失败：${error.message}` : '数据库连接失败，请重试'
+      )
+      setDbKeyStatusKind('error')
+      if (databaseConnectionMode === 'automatic') setConnectionGuideStep(5)
      setBootState('login')
      setStartupProgress(null)
-      alert('Error connecting to database')
    } finally {
-      setIsDatabaseConnecting(false)
+      if (operationId === connectionOperationRef.current) setIsDatabaseConnecting(false)
    }
  }

@@ -864,31 +969,42 @@ function App(): React.ReactElement {

  const handleAutoGetDbKey = async (): Promise<void> => {
    if (isFetchingDbKey) return
+    const operationId = ++connectionOperationRef.current
+    setConnectionGuideStep(4)
    setIsFetchingDbKey(true)
    setDbKeyStatus('正在准备获取密钥...')
    setDbKeyStatusKind('normal')
    setShowMacKeyFaq(false)
    try {
-      const result = await window.api.autoGetDbKey()
+      if (!selectedAccount) throw new Error('请先选择微信账号')
+      const result = await window.api.autoGetDbKey(selectedAccount.accountRoot)
+      if (operationId !== connectionOperationRef.current) return
      if (!result.success || !result.key) {
        setShowMacKeyFaq(result.code === 'SCAN_FAILED')
        throw new Error(result.error || '获取密钥失败')
      }
      setDbKey(result.key)
-      setDatabaseConnectionMode('manual')
+      setConnectionGuideStep(5)
      setDbKeyStatus(result.saved ? '密钥已获取并安全保存' : result.warning || '密钥已获取')
      setDbKeyStatusKind(result.saved ? 'success' : 'normal')
    } catch (error) {
+      if (operationId !== connectionOperationRef.current) return
      setDbKeyStatus(error instanceof Error ? error.message : String(error))
      setDbKeyStatusKind('error')
+      setConnectionGuideStep(3)
    } finally {
-      setIsFetchingDbKey(false)
+      if (operationId === connectionOperationRef.current) setIsFetchingDbKey(false)
    }
  }

  const handlePasteAndSaveDbKey = async (): Promise<void> => {
    setShowMacKeyFaq(false)
-    const result = await window.api.pasteAndSaveDbKey()
+    if (!selectedAccount) {
+      setDbKeyStatus('请先选择微信账号')
+      setDbKeyStatusKind('error')
+      return
+    }
+    const result = await window.api.pasteAndSaveDbKey(selectedAccount.accountRoot)
    if (result.success && result.key) {
      setDbKey(result.key)
      setDatabaseConnectionMode('manual')
@@ -902,7 +1018,8 @@ function App(): React.ReactElement {

  const handleClearSavedDbKey = async (): Promise<void> => {
    setShowMacKeyFaq(false)
-    const result = await window.api.clearSavedDbKey()
+    if (!selectedAccount) return
+    const result = await window.api.clearSavedDbKey(selectedAccount.accountRoot)
    if (!result.success) {
      setDbKeyStatus(result.error || '清除密钥失败')
      setDbKeyStatusKind('error')
@@ -935,12 +1052,54 @@ function App(): React.ReactElement {
    setStartupProgress(null)
  }

+  const handleSwitchAccount = async (account: WechatAccountCandidate): Promise<void> => {
+    connectionOperationRef.current += 1
+    await window.api.disconnectDb({ closeNative: true })
+    setIsAuthenticated(false)
+    setIsDatabaseConnected(false)
+    setSelectedContact(null)
+    setMessages([])
+    setContacts([])
+    setFilteredContacts([])
+    setContentFilter('')
+    setSelfInfo(null)
+    setReportSourceContact(null)
+    setExportTasks([])
+    messageHistoryRef.current = []
+    messagesRef.current = []
+    selectedContactMd5Ref.current = ''
+    currentGroupSnapshotRef.current = null
+    groupMemberMetaRef.current = {}
+    syntheticGroupMessagesRef.current = {}
+    setDiscoveredAccounts((current) =>
+      current.some((item) => item.id === account.id) ? current : [account]
+    )
+    setSelectedAccountId(account.id)
+    setDbRootInput(account.accountRoot)
+    await window.api.setSettings({ dbRoot: account.accountRoot, imageKeyRoot: account.accountRoot })
+    const saved = await window.api.getSavedDbKey(account.accountRoot)
+    if (!saved.success || !saved.key) {
+      setDbKey('')
+      setDatabaseConnectionMode('automatic')
+      setBootState('login')
+      setConnectionGuideStep(3)
+      setDbKeyStatus('该账号尚无可用密钥，请为所选账号获取密钥')
+      setDbKeyStatusKind('normal')
+      return
+    }
+    setDbKey(saved.key)
+    setDatabaseConnectionMode('manual')
+    setBootState('login')
+    await handleLogin(saved.key, account.accountRoot)
+  }
+
  const handleSelectContact = async (contact: Contact, forceLive = false): Promise<void> => {
    setArchiveJumpTime(null)
    setSelectedContact(contact)
    selectedContactMd5Ref.current = contact.md5
    currentGroupSnapshotRef.current = null
    setIsMessagesLoading(true)
+    setMessageHistoryStatus('idle')
    const cachedPage = await window.api.getCachedMessagePage(contact.md5)
    const cachedMsgs = cachedPage.messages
    if (selectedContactMd5Ref.current !== contact.md5) return
@@ -1052,7 +1211,7 @@ function App(): React.ReactElement {

  const handleLoadOlderMessages = async (): Promise<void> => {
    const contact = selectedContact
-    if (!contact || messagesRef.current.length === 0) return
+    if (!contact || messagesRef.current.length === 0 || messageHistoryStatus === 'end') return
    if (messagePrefetchRef.current) await messagePrefetchRef.current
    if (selectedContactMd5Ref.current !== contact.md5) return
    const currentMessages = messagesRef.current
@@ -1089,6 +1248,7 @@ function App(): React.ReactElement {
            limit: MESSAGE_PAGE_SIZE
          })
      if (selectedContactMd5Ref.current !== contact.md5) return
+      setMessageHistoryStatus(olderMessages.length === 0 ? 'end' : 'idle')
      messageHistoryRef.current = mergeMessagePages(olderMessages, historyMessages)
      setMessages((current) =>
        applyGroupMemberMeta(
@@ -1098,6 +1258,7 @@ function App(): React.ReactElement {
      )
    } catch (error) {
      console.warn('[Messages] older page load failed:', error)
+      if (selectedContactMd5Ref.current === contact.md5) setMessageHistoryStatus('error')
    } finally {
      if (selectedContactMd5Ref.current === contact.md5) setIsMessagesLoading(false)
    }
@@ -1434,6 +1595,7 @@ function App(): React.ReactElement {
        contact={selectedContact}
        messages={messages}
        isLoadingMessages={isMessagesLoading}
+        messageHistoryStatus={messageHistoryStatus}
        contentFilter={contentFilter}
        onContentFilterChange={setContentFilter}
        onRefresh={() => selectedContact && handleSelectContact(selectedContact, true)}
@@ -1561,6 +1723,7 @@ function App(): React.ReactElement {
            onNotice={setReportNotice}
            onOpenSettings={openSettings}
            onAppearanceChange={handleAppearanceChange}
+            onSwitchAccount={handleSwitchAccount}
          />
        )
      case 'search':
@@ -1675,15 +1838,80 @@ function App(): React.ReactElement {
        dbRoot={dbRootInput}
        showDbKey={showDbKey}
        isFetching={isFetchingDbKey}
+        isConnecting={isDatabaseConnecting}
+        guideStep={connectionGuideStep}
+        environment={databaseEnvironment}
+        accounts={discoveredAccounts}
+        selectedAccountId={selectedAccountId}
        status={dbKeyStatus}
        statusKind={dbKeyStatusKind}
        showMacKeyFaq={showMacKeyFaq}
        macKeyFaqUrl={MAC_KEY_FAQ_URL}
        onModeChange={setDatabaseConnectionMode}
        onDbKeyChange={setDbKey}
-        onDbRootChange={setDbRootInput}
+        onDbRootChange={(value) => {
+          setDbRootInput(value)
+          setDiscoveredAccounts([])
+          setSelectedAccountId('')
+        }}
+        onSelectAccount={(account) => {
+          setSelectedAccountId(account.id)
+          setDbKey('')
+          void window.api.getSavedDbKey(account.accountRoot).then((result) => {
+            if (result.success && result.key) setDbKey(result.key)
+          })
+        }}
+        onSelectDbRoot={() => {
+          void window.api.selectDbRoot().then((result) => {
+            if (!result.canceled && result.path) {
+              setDbRootInput(result.path)
+              void window.api.discoverAccounts(result.path).then((discovery) => {
+                if (!discovery.success) {
+                  setDiscoveredAccounts([])
+                  setSelectedAccountId('')
+                  setDbKeyStatus(discovery.error || '账号目录识别失败')
+                  setDbKeyStatusKind('error')
+                  return
+                }
+                setDiscoveredAccounts(discovery.accounts)
+                setSelectedAccountId(discovery.preselectedAccountId || '')
+              })
+            }
+          })
+        }}
        onToggleDbKey={() => setShowDbKey((visible) => !visible)}
        onAutoGetKey={handleAutoGetDbKey}
+        onRefreshEnvironment={() => void refreshConnectionEnvironment()}
+        onGuideNext={() =>
+          setConnectionGuideStep((current) => (current === 1 ? 2 : current === 2 ? 3 : current))
+        }
+        onGuideBack={() =>
+          setConnectionGuideStep((current) =>
+            current === 5 ? 3 : current > 1 ? ((current - 1) as 1 | 2 | 3 | 4 | 5 | 6) : 1
+          )
+        }
+        onGuideCancel={() => {
+          connectionOperationRef.current += 1
+          setIsFetchingDbKey(false)
+          setIsDatabaseConnecting(false)
+          setBootState('login')
+          setStartupProgress(null)
+          setConnectionGuideStep(1)
+          setDbKeyStatus('已取消，可以重新检查环境')
+          setDbKeyStatusKind('normal')
+        }}
+        onValidateConnection={() => void handleLogin()}
+        onCopyDiagnostics={() => {
+          if (!databaseEnvironment?.diagnosticSummary) {
+            setDbKeyStatus('诊断信息尚未准备好，请先重新检查环境')
+            setDbKeyStatusKind('error')
+            return
+          }
+          void window.api.copyText(databaseEnvironment.diagnosticSummary).then(() => {
+            setDbKeyStatus('脱敏诊断摘要已复制')
+            setDbKeyStatusKind('success')
+          })
+        }}
        onManualConnect={() => handleLogin()}
        onPasteKey={handlePasteAndSaveDbKey}
        onClearKey={handleClearSavedDbKey}
@@ -10,6 +10,7 @@ interface ChatWindowProps {
  contact: Contact | null
  messages: Message[]
  isLoadingMessages?: boolean
+  messageHistoryStatus?: 'idle' | 'end' | 'error'
  contentFilter?: string
  onContentFilterChange?: (keyword: string) => void
  onRefresh?: () => void
@@ -25,6 +26,7 @@ const ChatWindow: React.FC<ChatWindowProps> = ({
  contact,
  messages,
  isLoadingMessages,
+  messageHistoryStatus,
  contentFilter,
  onContentFilterChange,
  onRefresh,
@@ -205,6 +207,7 @@ const ChatWindow: React.FC<ChatWindowProps> = ({
        messages={filteredMessages}
        hiddenMessageCount={0}
        isLoadingMessages={isLoadingMessages}
+        messageHistoryStatus={messageHistoryStatus}
        isGroupChat={isGroupChat}
        showAvatar={showAvatar}
        listRef={messageListRef}
@@ -1,4 +1,5 @@
 import React from 'react'
+import type { DatabaseKeyEnvironment, WechatAccountCandidate } from '../../../shared/database-key'

 const GUIDE_URL =
  'https://github.com/Wxw-Gu/WechatExplorer/blob/main/docs/user-guide/getting-started.md'
@@ -13,6 +14,11 @@ interface DatabaseConnectionPageProps {
  dbRoot: string
  showDbKey: boolean
  isFetching: boolean
+  isConnecting: boolean
+  guideStep: 1 | 2 | 3 | 4 | 5 | 6
+  environment?: DatabaseKeyEnvironment
+  accounts: WechatAccountCandidate[]
+  selectedAccountId: string
  status: string
  statusKind: DatabaseConnectionStatusKind
  showMacKeyFaq: boolean
@@ -20,8 +26,16 @@ interface DatabaseConnectionPageProps {
  onModeChange: (mode: DatabaseConnectionMode) => void
  onDbKeyChange: (value: string) => void
  onDbRootChange: (value: string) => void
+  onSelectAccount: (account: WechatAccountCandidate) => void
+  onSelectDbRoot: () => void
  onToggleDbKey: () => void
  onAutoGetKey: () => void
+  onRefreshEnvironment: () => void
+  onGuideNext: () => void
+  onGuideBack: () => void
+  onGuideCancel: () => void
+  onValidateConnection: () => void
+  onCopyDiagnostics: () => void
  onManualConnect: () => void
  onPasteKey: () => void
  onClearKey: () => void
@@ -92,6 +106,11 @@ export function DatabaseConnectionPage({
  dbRoot,
  showDbKey,
  isFetching,
+  isConnecting,
+  guideStep,
+  environment,
+  accounts = [],
+  selectedAccountId = '',
  status,
  statusKind,
  showMacKeyFaq,
@@ -99,8 +118,16 @@ export function DatabaseConnectionPage({
  onModeChange,
  onDbKeyChange,
  onDbRootChange,
+  onSelectAccount,
+  onSelectDbRoot,
  onToggleDbKey,
  onAutoGetKey,
+  onRefreshEnvironment,
+  onGuideNext,
+  onGuideBack,
+  onGuideCancel,
+  onValidateConnection,
+  onCopyDiagnostics,
  onManualConnect,
  onPasteKey,
  onClearKey
@@ -146,27 +173,27 @@ export function DatabaseConnectionPage({
          <div className="database-login-start">
            <p className="database-login-eyebrow">第一次使用</p>
            <h2>开始连接微信</h2>
-            <p>跟着下面 3 步操作，通常几分钟即可完成连接。</p>
+            <p>按顺序检查环境、准备连接组件并验证数据库，通常几分钟即可完成。</p>
            <ol>
              <li>
                <span>1</span>
                <div>
-                  <strong>确认微信数据目录</strong>
-                  <small>没有自动找到时，可在设置中手动选择</small>
+                  <strong>检查本机环境</strong>
+                  <small>确认微信版本、数据目录和运行状态</small>
                </div>
              </li>
              <li>
                <span>2</span>
                <div>
-                  <strong>让微信停在登录页面</strong>
-                  <small>不要在获取密钥前完成登录</small>
+                  <strong>准备连接组件</strong>
+                  <small>页面会按当前系统给出对应步骤</small>
                </div>
              </li>
              <li>
                <span>3</span>
                <div>
-                  <strong>点击自动获取密钥</strong>
-                  <small>提示可以登录后，再回到微信完成登录</small>
+                  <strong>登录并验证连接</strong>
+                  <small>验证通过后进入主界面</small>
                </div>
              </li>
            </ol>
@@ -202,6 +229,11 @@ export function DatabaseConnectionPage({

          {mode === 'automatic' ? (
            <div className="database-login-auto" role="tabpanel">
+              <div className="database-login-guide-progress" aria-label={`连接进度 ${guideStep}/6`}>
+                {Array.from({ length: 6 }, (_, index) => (
+                  <span key={index} className={index + 1 <= guideStep ? 'active' : ''} />
+                ))}
+              </div>
              <div className={`database-login-state-card ${statusKind}`}>
                <div className="database-login-state-heading">
                  <span className="database-login-state-icon">
@@ -209,19 +241,46 @@ export function DatabaseConnectionPage({
                  </span>
                  <div>
                    <strong>
-                      {statusKind === 'error' ? '未能获取数据库密钥' : '已准备检测微信数据库'}
+                      {statusKind === 'error'
+                        ? '当前步骤未完成'
+                        : [
+                            '检查本机环境',
+                            '让微信停在登录页面',
+                            '确认开始准备',
+                            `正在完成 ${isMac ? 'macOS' : 'Windows'} 授权`,
+                            '现在可以登录微信',
+                            '验证数据库连接'
+                          ][guideStep - 1]}
                    </strong>
                    <p>
                      {statusKind === 'error'
                        ? status
-                        : status || '请保持微信客户端正在运行，系统将尝试安全获取数据库密钥。'}
+                        : status ||
+                          [
+                            '确认下方检测结果；没有找到目录时可以手动选择。',
+                            '请退出当前微信账号，让微信停留在登录页面，然后点击“我已准备好”。',
+                            '开始后请按页面提示完成系统授权。',
+                            '正在准备连接组件，请不要关闭微信或 WechatExplorer。',
+                            '请回到微信完成登录，登录成功后再回来验证。',
+                            '正在验证密钥和本地数据库，请稍候。'
+                          ][guideStep - 1]}
                    </p>
                  </div>
                </div>
+                {guideStep === 1 && (
+                  <>
                    <dl className="database-login-diagnostics">
                      <div>
-                    <dt>微信客户端</dt>
-                    <dd>{isFetching ? '正在检测' : '等待检测'}</dd>
+                        <dt>操作系统</dt>
+                        <dd>{environment?.osVersion || (isMac ? 'macOS' : 'Windows')}</dd>
+                      </div>
+                      <div>
+                        <dt>微信版本</dt>
+                        <dd>{environment?.wechatVersion || '未检测到'}</dd>
+                      </div>
+                      <div>
+                        <dt>数据结构</dt>
+                        <dd>{environment?.dataStructureVersion || '未检测到'}</dd>
                      </div>
                      <div>
                        <dt>
@@ -244,22 +303,144 @@ export function DatabaseConnectionPage({
                              {dbRoot || defaultPath}
                            </span>
                          </span>
+                          <button
+                            type="button"
+                            className="database-login-path-select"
+                            onClick={onSelectDbRoot}
+                            disabled={isFetching || isConnecting}
+                          >
+                            选择目录
+                          </button>
                        </dd>
                      </div>
                      <div>
-                    <dt>数据库状态</dt>
-                    <dd>{statusKind === 'error' ? '无法连接' : '准备连接'}</dd>
+                        <dt>微信状态</dt>
+                        <dd>{environment?.wechatRunning ? '运行中' : '未检测到'}</dd>
                      </div>
                    </dl>
+                    {accounts.length > 0 && (
+                      <section className="database-account-list" aria-label="选择微信账号">
+                        <h3>选择微信账号</h3>
+                        {accounts.map((account) => (
+                          <button
+                            type="button"
+                            key={account.id}
+                            className={`database-account-card ${selectedAccountId === account.id ? 'selected' : ''}`}
+                            aria-pressed={selectedAccountId === account.id}
+                            onClick={() => onSelectAccount(account)}
+                          >
+                            <span className="database-account-avatar">
+                              {account.avatar ? (
+                                <img src={account.avatar} alt="" />
+                              ) : (
+                                (account.nickname || '?').charAt(0)
+                              )}
+                            </span>
+                            <span className="database-account-identity">
+                              <strong>{account.nickname || '昵称未识别'}</strong>
+                              <small>{account.wxid || 'wxid 未识别'}</small>
+                              <code title={account.accountRoot}>{account.accountRoot}</code>
+                            </span>
+                            <span className="database-account-status">
+                              {account.hasSavedDbKey ? '已有可用密钥' : '尚无可用密钥'}
+                              <small>
+                                {account.loginStatus === 'current'
+                                  ? '当前已连接账号'
+                                  : account.loginStatus === 'other'
+                                    ? '非当前账号'
+                                    : '登录状态未确认'}
+                              </small>
+                            </span>
+                          </button>
+                        ))}
+                        <button
+                          type="button"
+                          className="database-login-secondary"
+                          onClick={onSelectDbRoot}
+                          disabled={isFetching || isConnecting}
+                        >
+                          选择其他账号
+                        </button>
+                      </section>
+                    )}
+                  </>
+                )}
              </div>
+              {guideStep === 1 && (
+                <>
                  <button
                    type="button"
                    className="database-login-primary"
-                onClick={onAutoGetKey}
-                disabled={isFetching}
+                    onClick={onGuideNext}
+                    disabled={!selectedAccountId}
                  >
-                {isFetching ? '正在获取密钥…' : statusKind === 'error' ? '重新检测' : '开始获取'}
+                    检查完成，继续
                  </button>
+                  <button
+                    type="button"
+                    className="database-login-secondary"
+                    onClick={onRefreshEnvironment}
+                  >
+                    重新检查环境
+                  </button>
+                  <button
+                    type="button"
+                    className="database-login-text-action"
+                    onClick={onCopyDiagnostics}
+                  >
+                    复制脱敏诊断摘要
+                  </button>
+                </>
+              )}
+              {guideStep === 2 && (
+                <button type="button" className="database-login-primary" onClick={onGuideNext}>
+                  我已准备好
+                </button>
+              )}
+              {guideStep === 3 && (
+                <button type="button" className="database-login-primary" onClick={onAutoGetKey}>
+                  开始准备连接组件
+                </button>
+              )}
+              {guideStep === 4 && (
+                <button type="button" className="database-login-primary" disabled>
+                  正在准备连接组件…
+                </button>
+              )}
+              {guideStep === 5 && (
+                <button
+                  type="button"
+                  className="database-login-primary"
+                  onClick={onValidateConnection}
+                  disabled={!dbKey || isConnecting}
+                >
+                  {isConnecting ? '正在验证…' : '微信已登录，验证连接'}
+                </button>
+              )}
+              {guideStep === 6 && (
+                <button type="button" className="database-login-primary" disabled>
+                  正在验证数据库…
+                </button>
+              )}
+              {guideStep > 1 && !isFetching && !isConnecting && (
+                <div className="database-login-guide-actions">
+                  <button type="button" onClick={onGuideBack}>
+                    返回上一步
+                  </button>
+                  <button type="button" onClick={onGuideCancel}>
+                    取消并重新检查
+                  </button>
+                </div>
+              )}
+              {(isFetching || isConnecting) && (
+                <button
+                  type="button"
+                  className="database-login-text-action"
+                  onClick={onGuideCancel}
+                >
+                  取消
+                </button>
+              )}
              <p className="database-login-platform-note">
                {isMac ? (
                  <>
@@ -311,8 +492,10 @@ export function DatabaseConnectionPage({
                    微信数据目录
                    <StoragePathHelp />
                  </label>
+                  <div className="database-login-root-control">
                    <input
                      id="database-login-root"
+                      aria-label="微信数据目录"
                      value={dbRoot}
                      onChange={(event) => onDbRootChange(event.target.value)}
                      placeholder={defaultPath}
@@ -320,6 +503,10 @@ export function DatabaseConnectionPage({
                      spellCheck={false}
                      onFocus={(event) => event.currentTarget.select()}
                    />
+                    <button type="button" onClick={onSelectDbRoot} disabled={isConnecting}>
+                      选择目录
+                    </button>
+                  </div>
                </div>
              )}
              {status && <div className={`database-login-message ${statusKind}`}>{status}</div>}
@@ -327,11 +514,25 @@ export function DatabaseConnectionPage({
                type="button"
                className="database-login-primary"
                onClick={onManualConnect}
-                disabled={!keyIsValid}
+                disabled={!keyIsValid || isConnecting}
              >
-                连接数据库
+                {isConnecting ? '正在连接…' : '连接数据库'}
              </button>
-              <button type="button" className="database-login-secondary" onClick={onPasteKey}>
+              {isConnecting && (
+                <button
+                  type="button"
+                  className="database-login-text-action"
+                  onClick={onGuideCancel}
+                >
+                  取消连接
+                </button>
+              )}
+              <button
+                type="button"
+                className="database-login-secondary"
+                onClick={onPasteKey}
+                disabled={isConnecting}
+              >
                从剪贴板粘贴并安全保存
              </button>
            </div>
@@ -9,6 +9,7 @@ interface MessageListProps {
  messages: Message[]
  hiddenMessageCount: number
  isLoadingMessages?: boolean
+  messageHistoryStatus?: 'idle' | 'end' | 'error'
  isGroupChat: boolean
  showAvatar: boolean
  listRef: React.RefObject<HTMLDivElement | null>
@@ -24,6 +25,7 @@ export function MessageList({
  messages,
  hiddenMessageCount,
  isLoadingMessages,
+  messageHistoryStatus,
  isGroupChat,
  showAvatar,
  listRef,
@@ -119,6 +121,18 @@ export function MessageList({
  return (
    <div className="message-list wechat-message-list" ref={listRef} onScroll={handleScroll}>
      {isLoadingMessages && <div className="message-loading-pill">正在加载聊天记录...</div>}
+      {messageHistoryStatus === 'end' && (
+        <div className="wechat-system-message-row">
+          <div className="wechat-system-message">已显示本地数据库中的最早记录</div>
+        </div>
+      )}
+      {messageHistoryStatus === 'error' && (
+        <div className="wechat-system-message-row">
+          <div className="wechat-system-message">
+            无法读取更早记录，请检查数据目录或当前微信数据版本
+          </div>
+        </div>
+      )}
      {hiddenMessageCount > 0 && (
        <div className="wechat-system-message-row">
          <div className="wechat-system-message">
@@ -41,7 +41,7 @@ export function ExportWorkspace({
  const [includeAvatars, setIncludeAvatars] = useState(true)
  const [preferOriginal, setPreferOriginal] = useState(true)
  const [fallbackThumbnail, setFallbackThumbnail] = useState(true)
-  const [keepMissing, setKeepMissing] = useState(false)
+  const [keepMissing, setKeepMissing] = useState(true)
  const [format, setFormat] = useState<ExportFormat>('csv')
  const [zip, setZip] = useState(false)
  const [fileName, setFileName] = useState('')
@@ -158,6 +158,8 @@ export function ExportWorkspace({

  const handleStart = async (): Promise<void> => {
    if (!activeContact || status === 'running') return
+    // Runs only from the export button event; a fresh id is required for each job.
+    // eslint-disable-next-line react-hooks/purity
    const nextJobId = `export-${Date.now()}`
    setJobId(nextJobId)
    setProgress(null)
@@ -204,6 +206,9 @@ export function ExportWorkspace({
          : undefined,
      kinds: Array.from(selectedKinds) as ExportMessageKind[],
      includeMedia,
+      preferOriginal,
+      fallbackThumbnail,
+      keepMissing,
      includeAvatars,
      avatarUrls: exportAvatarUrls,
      nameMode,
@@ -303,20 +308,39 @@ export function ExportWorkspace({
            <h3>导出格式</h3>
            <div className="export-format-grid">
              {formatOrder.map((value) => (
-                <button key={value} type="button" className={format === value ? 'active' : ''} onClick={() => setFormat(value)}>
+                <button
+                  key={value}
+                  type="button"
+                  className={format === value ? 'active' : ''}
+                  onClick={() => setFormat(value)}
+                >
                  <strong>{formatLabels[value].label}</strong>
                  {formatLabels[value].hint && <small>{formatLabels[value].hint}</small>}
                </button>
              ))}
            </div>
-            <p className="export-helper-text">CSV 默认最快；HTML 会包含图片、引用和其他媒体，导出时间可能较长。</p>
+            <p className="export-helper-text">
+              CSV 默认最快；HTML 会包含图片、引用和其他媒体，导出时间可能较长。
+            </p>
            {format === 'html' && (
              <div className="export-html-options">
                <label>
-                  <input type="radio" name="html-package-top" checked={!zip} onChange={() => setZip(false)} /> HTML 资源包
+                  <input
+                    type="radio"
+                    name="html-package-top"
+                    checked={!zip}
+                    onChange={() => setZip(false)}
+                  />{' '}
+                  HTML 资源包
                </label>
                <label>
-                  <input type="radio" name="html-package-top" checked={zip} onChange={() => setZip(true)} /> HTML 资源包并压缩为 ZIP
+                  <input
+                    type="radio"
+                    name="html-package-top"
+                    checked={zip}
+                    onChange={() => setZip(true)}
+                  />{' '}
+                  HTML 资源包并压缩为 ZIP
                </label>
              </div>
            )}
@@ -383,19 +407,13 @@ export function ExportWorkspace({
            <h3>消息内容</h3>
            <div className="export-kind-grid">
              {messageKinds.map(([value, label]) => (
-                <label key={value} className={`export-check-row ${value === 'video' ? 'unsupported' : ''}`}>
+                <label key={value} className="export-check-row">
                  <input
                    type="checkbox"
-                    checked={value !== 'video' && selectedKinds.has(value)}
-                    disabled={value === 'video'}
+                    checked={selectedKinds.has(value)}
                    onChange={() => toggleKind(value)}
                  />
                  <span>{label}</span>
-                  {value === 'video' && (
-                    <span className="export-unsupported-hint" title="当前版本暂不支持视频导出" aria-label="当前版本暂不支持视频导出">
-                      !
-                    </span>
-                  )}
                </label>
              ))}
            </div>
@@ -429,7 +447,9 @@ export function ExportWorkspace({
                onChange={(event) => setIncludeMedia(event.target.checked)}
              />
            </label>
-            <div className={`export-media-options ${includeMedia && format === 'html' ? '' : 'disabled'}`}>
+            <div
+              className={`export-media-options ${includeMedia && format === 'html' ? '' : 'disabled'}`}
+            >
              <label className="export-check-row">
                <input
                  type="checkbox"
@@ -458,7 +478,9 @@ export function ExportWorkspace({
                <span>媒体缺失时保留占位说明</span>
              </label>
            </div>
-            <p className="export-helper-text">资源文件仅在 HTML 导出中生效，CSV、JSON 和 Markdown 只保留文本内容。</p>
+            <p className="export-helper-text">
+              资源文件仅在 HTML 导出中生效，CSV、JSON 和 Markdown 只保留文本内容。
+            </p>
            <div className="export-resource-statuses">
              <span>图片解密：已就绪</span>
              <span>视频资源：可用</span>
@@ -30,7 +30,8 @@ export function SettingsWorkspace({
  onAIRuntimeChange,
  onNotice,
  onOpenSettings,
-  onAppearanceChange
+  onAppearanceChange,
+  onSwitchAccount
 }: {
  selectedCategory: SettingsCategoryId
  onCategoryChange: (id: SettingsCategoryId) => void
@@ -47,7 +48,13 @@ export function SettingsWorkspace({
  onAIRuntimeChange: (config: AIRuntimeModelConfig) => void
  onNotice: (message: string) => void
  onOpenSettings: () => void
-  onAppearanceChange: (settings: { theme: 'system' | 'light' | 'dark'; compactMode: boolean }) => void
+  onAppearanceChange: (settings: {
+    theme: 'system' | 'light' | 'dark'
+    compactMode: boolean
+  }) => void
+  onSwitchAccount: (
+    account: import('../../../../shared/database-key').WechatAccountCandidate
+  ) => Promise<void>
 }): React.ReactElement {
  const renderSelectedPage = (): React.ReactElement => {
    switch (selectedCategory) {
@@ -59,6 +66,7 @@ export function SettingsWorkspace({
            dbConnecting={dbConnecting}
            selfInfo={selfInfo}
            onNotice={onNotice}
+            onSwitchAccount={onSwitchAccount}
          />
        )
      case 'database-key':
@@ -87,9 +95,7 @@ export function SettingsWorkspace({
      case 'cache-cleanup':
        return <CacheCleanupPage onNotice={onNotice} />
      case 'appearance':
-        return (
-          <AppearancePage onNotice={onNotice} onAppearanceChange={onAppearanceChange} />
-        )
+        return <AppearancePage onNotice={onNotice} onAppearanceChange={onAppearanceChange} />
      case 'about':
        return <AboutPage onNotice={onNotice} />
      default:
@@ -25,7 +25,8 @@ export function AccountOverview({
  isChecking,
  onCheck,
  onOpenDirectory,
-  onCopyDirectory
+  onCopyDirectory,
+  onSwitchAccount
 }: {
  selfInfo: SettingsSelfInfo | null
  connectionStatus: ConnectionOverviewStatus
@@ -34,6 +35,7 @@ export function AccountOverview({
  onCheck: () => void
  onOpenDirectory: () => void
  onCopyDirectory: () => void
+  onSwitchAccount: () => void
 }): React.ReactElement {
  const accountRoot = selfInfo?.accountRoot || ''
  return (
@@ -83,6 +85,9 @@ export function AccountOverview({
        >
          打开账号目录
        </button>
+        <button type="button" className="api-secondary-button" onClick={onSwitchAccount}>
+          切换账号
+        </button>
      </div>

      <div className="settings-account-root">
@@ -36,14 +36,14 @@ export function useDatabaseKeyController({
  }, [])

  const refreshStorage = useCallback(async (): Promise<void> => {
-    const result = await window.api.getSavedDbKey()
+    const result = await window.api.getSavedDbKey(selfInfo?.accountRoot || '')
    dispatch({
      type: 'STORAGE_LOADED',
      saved: result.saved,
      encryptionAvailable: result.encryptionAvailable,
      error: result.success ? undefined : result.error
    })
-  }, [])
+  }, [selfInfo?.accountRoot])

  useEffect(() => {
    void Promise.all([refreshStorage(), refreshEnvironment()])
@@ -109,7 +109,8 @@ export function useDatabaseKeyController({
  const saveKey = useCallback(async (): Promise<void> => {
    if (state.status !== 'valid') return
    dispatch({ type: 'SAVE_START' })
-    const saved = await window.api.saveDbKey(dbKey)
+    const accountRoot = selfInfo?.accountRoot || ''
+    const saved = await window.api.saveDbKey(accountRoot, dbKey)
    if (!saved.success || !saved.key) {
      dispatch({
        type: 'SAVE_ERROR',
@@ -117,12 +118,12 @@ export function useDatabaseKeyController({
      })
      return
    }
-    const stored = await window.api.getSavedDbKey()
+    const stored = await window.api.getSavedDbKey(accountRoot)
    if (!stored.success || !stored.saved || !stored.key) {
      dispatch({ type: 'SAVE_ERROR', error: '无法确认密钥保存状态' })
      return
    }
-    const initialized = await window.api.initDb(stored.key)
+    const initialized = await window.api.initDb(stored.key, accountRoot)
    const connected = typeof initialized === 'boolean' ? initialized : initialized.success
    onDbKeyChange(stored.key)
    onDatabaseConnectionChange(connected)
@@ -148,13 +149,14 @@ export function useDatabaseKeyController({
    onNotice,
    onSelfInfoChange,
    refreshEnvironment,
+    selfInfo?.accountRoot,
    state.status
  ])

  const autoDetectKey = useCallback(async (): Promise<void> => {
    dispatch({ type: 'AUTO_START' })
    await refreshEnvironment()
-    const result = await window.api.autoGetDbKey({ save: false })
+    const result = await window.api.autoGetDbKey(selfInfo?.accountRoot || '', { save: false })
    if (!result.success || !result.key) {
      dispatch({ type: 'AUTO_ERROR', error: result.error || '暂未找到有效密钥' })
      return
@@ -162,11 +164,11 @@ export function useDatabaseKeyController({
    onDbKeyChange(result.key)
    dispatch({ type: 'AUTO_SUCCESS' })
    await runValidation(result.key)
-  }, [onDbKeyChange, refreshEnvironment, runValidation])
+  }, [onDbKeyChange, refreshEnvironment, runValidation, selfInfo?.accountRoot])

  const clearSavedKey = useCallback(async (): Promise<void> => {
    dispatch({ type: 'CLEAR_START' })
-    const result = await window.api.clearSavedDbKey()
+    const result = await window.api.clearSavedDbKey(selfInfo?.accountRoot || '')
    if (!result.success) {
      dispatch({ type: 'CLEAR_ERROR', error: '清除密钥失败' })
      return
@@ -187,7 +189,8 @@ export function useDatabaseKeyController({
    onFilteredContactsChange,
    onNotice,
    onSelfInfoChange,
-    refreshEnvironment
+    refreshEnvironment,
+    selfInfo?.accountRoot
  ])

  const returnToLogin = useCallback(async (): Promise<void> => {
@@ -5,6 +5,7 @@ import { LocalPrivacyNotice } from '../account-database/LocalPrivacyNotice'
 import { useAccountDatabaseController } from '../account-database/useAccountDatabaseController'
 import type { ConnectionOverviewStatus } from '../account-database/types'
 import type { SettingsSelfInfo } from '../model/types'
+import type { WechatAccountCandidate } from '../../../../../shared/database-key'

 const STATUS_LABELS: Record<ConnectionOverviewStatus, string> = {
  checking: '正在检测',
@@ -19,13 +20,15 @@ export function AccountDatabasePage({
  dbReady,
  dbConnecting = false,
  selfInfo,
-  onNotice
+  onNotice,
+  onSwitchAccount
 }: {
  dbKey: string
  dbReady: boolean
  dbConnecting?: boolean
  selfInfo: SettingsSelfInfo | null
  onNotice: (message: string) => void
+  onSwitchAccount: (account: WechatAccountCandidate) => Promise<void>
 }): React.ReactElement {
  const controller = useAccountDatabaseController({
    dbKey,
@@ -35,6 +38,8 @@ export function AccountDatabasePage({
    onNotice
  })
  const [autoLogin, setAutoLogin] = useState(false)
+  const [switching, setSwitching] = useState(false)
+  const [accounts, setAccounts] = useState<WechatAccountCandidate[]>([])

  useEffect(() => {
    let active = true
@@ -56,6 +61,18 @@ export function AccountDatabasePage({
    onNotice(checked ? '已开启启动时自动连接' : '已关闭启动时自动连接')
  }

+  const openAccountSwitcher = async (): Promise<void> => {
+    if (!selfInfo?.accountRoot) return
+    const parentRoot = selfInfo.accountRoot.replace(/[\\/][^\\/]+[\\/]?$/, '')
+    const result = await window.api.discoverAccounts(parentRoot)
+    if (!result.success) {
+      onNotice(result.error || '无法读取账号列表')
+      return
+    }
+    setAccounts(result.accounts)
+    setSwitching(true)
+  }
+
  return (
    <div className="settings-page">
      <header className="settings-page-header">
@@ -79,7 +96,45 @@ export function AccountDatabasePage({
            onCheck={() => void controller.testConnection()}
            onOpenDirectory={() => void controller.openAccountDirectory()}
            onCopyDirectory={() => void controller.copyAccountDirectory()}
+            onSwitchAccount={() => void openAccountSwitcher()}
          />
+          {switching && (
+            <section className="settings-card database-account-list" aria-label="切换微信账号">
+              <h2>选择要切换的账号</h2>
+              {accounts.map((account) => (
+                <button
+                  type="button"
+                  key={account.id}
+                  className="database-account-card"
+                  disabled={account.accountRoot === selfInfo?.accountRoot}
+                  onClick={() => void onSwitchAccount(account).then(() => setSwitching(false))}
+                >
+                  <span className="database-account-avatar">
+                    {account.avatar ? (
+                      <img src={account.avatar} alt="" />
+                    ) : (
+                      (account.nickname || '?').charAt(0)
+                    )}
+                  </span>
+                  <span className="database-account-identity">
+                    <strong>{account.nickname || '昵称未识别'}</strong>
+                    <small>{account.wxid || 'wxid 未识别'}</small>
+                    <code>{account.accountRoot}</code>
+                  </span>
+                  <span className="database-account-status">
+                    {account.hasSavedDbKey ? '已有可用密钥' : '需要获取密钥'}
+                  </span>
+                </button>
+              ))}
+              <button
+                type="button"
+                className="api-secondary-button"
+                onClick={() => setSwitching(false)}
+              >
+                取消
+              </button>
+            </section>
+          )}
          <h2 className="settings-section-heading">连接健康检查</h2>
          <ConnectionHealthSection
            diagnostics={controller.diagnostics}
@@ -1185,7 +1185,7 @@
  min-width: 0;
  min-height: 0;
  overflow-y: auto;
-  padding: 48px clamp(40px, 7vw, 96px);
+  padding: 28px clamp(40px, 7vw, 96px);
  background: #fff;
 }

@@ -1195,7 +1195,7 @@
 }

 .database-login-start {
-  margin-bottom: 22px;
+  margin-bottom: 14px;

  h2 {
    margin: 0;
@@ -1285,7 +1285,7 @@
  grid-template-columns: repeat(2, 1fr);
  gap: 4px;
  padding: 4px;
-  margin-bottom: 28px;
+  margin-bottom: 18px;
  border: 1px solid var(--login-border);
  border-radius: 8px;
  background: #e9eeeb;
@@ -1410,6 +1410,58 @@
  text-align: right;
 }

+.database-login-guide-progress {
+  display: grid;
+  grid-template-columns: repeat(6, 1fr);
+  gap: 5px;
+  margin: 0 0 12px;
+}
+
+.database-login-guide-progress span {
+  height: 4px;
+  border-radius: 2px;
+  background: #dce4df;
+}
+
+.database-login-guide-progress span.active {
+  background: var(--login-primary);
+}
+
+.database-login-guide-actions {
+  display: flex;
+  justify-content: space-between;
+  gap: 12px;
+  margin-top: 14px;
+}
+
+.database-login-guide-actions button,
+.database-login-text-action {
+  padding: 5px 0;
+  border: 0;
+  color: var(--login-primary-dark);
+  background: transparent;
+  cursor: pointer;
+  font-size: 11px;
+}
+
+.database-login-text-action {
+  display: block;
+  width: 100%;
+  margin-top: 10px;
+  text-align: center;
+}
+
+.database-login-path-select {
+  margin-top: 5px;
+  padding: 4px 8px;
+  border: 1px solid var(--login-border);
+  border-radius: 5px;
+  color: var(--login-primary-dark);
+  background: #fff;
+  cursor: pointer;
+  font-size: 11px;
+}
+
 .database-login-path-input-wrap {
  position: relative;
  display: block;
@@ -1596,6 +1648,7 @@
 }

 .database-login-field > input,
+.database-login-root-control,
 .database-login-key-input {
  width: 100%;
  min-height: 42px;
@@ -1604,6 +1657,37 @@
  background: #fff;
 }

+.database-login-root-control {
+  display: grid;
+  grid-template-columns: minmax(0, 1fr) auto;
+  overflow: hidden;
+}
+
+.database-login-root-control input {
+  min-width: 0;
+  padding: 0 12px;
+  border: 0;
+  outline: 0;
+  color: var(--login-text);
+  background: transparent;
+  font-size: 13px;
+}
+
+.database-login-root-control button {
+  padding: 0 12px;
+  border: 0;
+  border-left: 1px solid var(--login-border);
+  color: var(--login-primary-dark);
+  background: var(--login-surface-low);
+  cursor: pointer;
+}
+
+.database-login-root-control button:disabled,
+.database-login-path-select:disabled {
+  cursor: not-allowed;
+  opacity: 0.55;
+}
+
 .database-login-field > input {
  padding: 0 12px;
  color: var(--login-text);
@@ -1617,6 +1701,7 @@
 }

 .database-login-key-input:focus-within,
+.database-login-root-control:focus-within,
 .database-login-field > input:focus {
  border-color: var(--login-primary);
  box-shadow: 0 0 0 3px rgba(36, 122, 99, 0.1);
@@ -1969,3 +2054,70 @@
    pointer-events: none;
  }
 }
+.database-account-list {
+  display: grid;
+  gap: 10px;
+  margin: 14px 0;
+
+  h3 {
+    margin: 0;
+    font-size: 14px;
+  }
+}
+
+.database-account-card {
+  width: 100%;
+  display: grid;
+  grid-template-columns: 44px minmax(0, 1fr) auto;
+  gap: 12px;
+  align-items: center;
+  padding: 12px;
+  border: 1px solid var(--border-color, #d8e2dc);
+  border-radius: 8px;
+  background: transparent;
+  color: inherit;
+  text-align: left;
+  cursor: pointer;
+
+  &.selected {
+    border-color: #176b57;
+    box-shadow: 0 0 0 2px #176b5720;
+  }
+}
+
+.database-account-avatar {
+  width: 44px;
+  height: 44px;
+  display: grid;
+  place-items: center;
+  overflow: hidden;
+  border-radius: 6px;
+  background: #dcebe4;
+
+  img {
+    width: 100%;
+    height: 100%;
+    object-fit: cover;
+  }
+}
+
+.database-account-identity,
+.database-account-status {
+  display: grid;
+  gap: 3px;
+  min-width: 0;
+
+  small,
+  code {
+    color: var(--text-secondary, #68766f);
+  }
+  code {
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+  }
+}
+
+.database-account-status {
+  text-align: right;
+}
@@ -0,0 +1,16 @@
+import type { DatabaseKeyEnvironment } from './database-key'
+
+export function buildSafeDiagnosticSummary(
+  environment: Omit<DatabaseKeyEnvironment, 'diagnosticSummary'>
+): string {
+  return [
+    `WechatExplorer: ${environment.appVersion}`,
+    `操作系统: ${environment.osVersion}`,
+    `微信客户端: ${environment.wechatVersion}`,
+    `数据结构: ${environment.dataStructureVersion}`,
+    `数据目录: ${environment.dataDirectoryDetected ? '已检测到' : '未检测到'}`,
+    `微信进程: ${environment.wechatRunning ? '运行中' : '未运行'}`,
+    `数据库连接: ${environment.dbConnected ? '已连接' : '未连接'}`,
+    `安全存储: ${environment.encryptionAvailable ? '可用' : '不可用'}`
+  ].join('\n')
+}
@@ -24,8 +24,36 @@ export interface DatabaseKeyStorageResult {
  encryptionAvailable: boolean
 }

+export type AccountLoginStatus = 'current' | 'other' | 'unknown'
+
+export interface WechatAccountCandidate {
+  id: string
+  accountRoot: string
+  directoryName: string
+  wxid?: string
+  nickname?: string
+  avatar?: string
+  hasSavedDbKey: boolean
+  loginStatus: AccountLoginStatus
+  selectedByInput: boolean
+}
+
+export interface AccountDiscoveryResult {
+  success: boolean
+  inputKind?: 'root' | 'account'
+  accounts: WechatAccountCandidate[]
+  preselectedAccountId?: string
+  error?: string
+}
+
 export interface DatabaseKeyEnvironment {
  platform: NodeJS.Platform
+  osVersion: string
+  appVersion: string
+  wechatVersion: string
+  dataStructureVersion: string
+  dataDirectoryDetected: boolean
+  diagnosticSummary: string
  autoDetectSupported: boolean
  wechatRunning: boolean
  accountIdentified: boolean
@@ -0,0 +1,22 @@
+import type { ExportRequest } from './export'
+
+export type ImageExportAttempt = {
+  allowThumbnail: boolean
+  preferThumbnail: boolean
+  fallback: boolean
+}
+
+export function getImageExportAttempts(
+  request: Pick<ExportRequest, 'preferOriginal' | 'fallbackThumbnail'>
+): ImageExportAttempt[] {
+  if (request.preferOriginal === false) {
+    return [{ allowThumbnail: true, preferThumbnail: true, fallback: false }]
+  }
+  const attempts: ImageExportAttempt[] = [
+    { allowThumbnail: false, preferThumbnail: false, fallback: false }
+  ]
+  if (request.fallbackThumbnail !== false) {
+    attempts.push({ allowThumbnail: true, preferThumbnail: true, fallback: true })
+  }
+  return attempts
+}
@@ -23,6 +23,9 @@ export interface ExportRequest {
  endTime?: number
  kinds: ExportMessageKind[]
  includeMedia: boolean
+  preferOriginal?: boolean
+  fallbackThumbnail?: boolean
+  keepMissing?: boolean
  includeAvatars?: boolean
  avatarUrls?: Record<string, string>
  nameMode?: ExportNameMode
@@ -14,6 +14,35 @@ function renderPage(
    dbRoot: '',
    showDbKey: false,
    isFetching: false,
+    isConnecting: false,
+    guideStep: 1 as const,
+    environment: {
+      platform: 'win32',
+      osVersion: 'Windows fixture',
+      appVersion: 'v2.1.6',
+      wechatVersion: '4.1.9.57',
+      dataStructureVersion: '微信 4.x（WCDB）',
+      dataDirectoryDetected: true,
+      diagnosticSummary: 'WechatExplorer: v2.1.6',
+      autoDetectSupported: true,
+      wechatRunning: true,
+      accountIdentified: false,
+      dbConnected: false,
+      encryptionAvailable: true
+    },
+    accounts: [
+      {
+        id: 'account-a',
+        accountRoot: 'C:\\fixture\\account-a',
+        directoryName: 'account-a',
+        nickname: '脱敏账号 A',
+        wxid: 'wxid_fixture_a',
+        hasSavedDbKey: true,
+        loginStatus: 'unknown' as const,
+        selectedByInput: true
+      }
+    ],
+    selectedAccountId: 'account-a',
    status: '',
    statusKind: 'normal' as const,
    showMacKeyFaq: false,
@@ -21,8 +50,16 @@ function renderPage(
    onModeChange: vi.fn(),
    onDbKeyChange: vi.fn(),
    onDbRootChange: vi.fn(),
+    onSelectAccount: vi.fn(),
+    onSelectDbRoot: vi.fn(),
    onToggleDbKey: vi.fn(),
    onAutoGetKey: vi.fn(),
+    onRefreshEnvironment: vi.fn(),
+    onGuideNext: vi.fn(),
+    onGuideBack: vi.fn(),
+    onGuideCancel: vi.fn(),
+    onValidateConnection: vi.fn(),
+    onCopyDiagnostics: vi.fn(),
    onManualConnect: vi.fn(),
    onPasteKey: vi.fn(),
    onClearKey: vi.fn(),
@@ -52,4 +89,48 @@ describe('DatabaseConnectionPage', () => {
    expect(onManualConnect).toHaveBeenCalledOnce()
    expect(screen.getByRole('button', { name: '从剪贴板粘贴并安全保存' })).toBeEnabled()
  })
+
+  it('restores directory editing and selection after a failed connection', async () => {
+    const onDbRootChange = vi.fn()
+    const onSelectDbRoot = vi.fn()
+    renderPage({
+      dbKey: 'b'.repeat(64),
+      dbRoot: 'Z:\\missing-wechat-data',
+      status: '微信数据目录不存在，请重新选择目录',
+      statusKind: 'error',
+      onDbRootChange,
+      onSelectDbRoot
+    })
+
+    await userEvent.clear(screen.getByLabelText('微信数据目录'))
+    await userEvent.type(screen.getByLabelText('微信数据目录'), 'C:\\fixture-account')
+    await userEvent.click(screen.getByRole('button', { name: '选择目录' }))
+
+    expect(onDbRootChange).toHaveBeenCalled()
+    expect(onSelectDbRoot).toHaveBeenCalledOnce()
+    expect(screen.getByRole('button', { name: '连接数据库' })).toBeEnabled()
+  })
+
+  it('supports forward, back, cancel and safe diagnostic actions in onboarding', async () => {
+    const onGuideNext = vi.fn()
+    const onCopyDiagnostics = vi.fn()
+    const { rerender, props } = renderPage({
+      mode: 'automatic',
+      guideStep: 1,
+      onGuideNext,
+      onCopyDiagnostics
+    })
+
+    expect(screen.getByText('4.1.9.57')).toBeVisible()
+    expect(screen.getByText('微信 4.x（WCDB）')).toBeVisible()
+    await userEvent.click(screen.getByRole('button', { name: '复制脱敏诊断摘要' }))
+    await userEvent.click(screen.getByRole('button', { name: '检查完成，继续' }))
+    expect(onCopyDiagnostics).toHaveBeenCalledOnce()
+    expect(onGuideNext).toHaveBeenCalledOnce()
+
+    rerender(<DatabaseConnectionPage {...props} mode="automatic" guideStep={2} />)
+    expect(screen.getByRole('button', { name: '我已准备好' })).toBeEnabled()
+    expect(screen.getByRole('button', { name: '返回上一步' })).toBeEnabled()
+    expect(screen.getByRole('button', { name: '取消并重新检查' })).toBeEnabled()
+  })
 })
@@ -23,13 +23,8 @@ test('KEY-01 KEY-02 invalid key remains recoverable and valid key enters the app
    await fixture.page.getByRole('tab', { name: /高级用户/ }).click()
    const keyInput = fixture.page.getByLabel('数据库密钥')
    await keyInput.fill('b'.repeat(64))
-    const errorDialog = fixture.page.waitForEvent('dialog')
-    await fixture.page
-      .getByRole('button', { name: '连接数据库' })
-      .evaluate((element: HTMLButtonElement) => element.click())
-    const dialog = await errorDialog
-    expect(dialog.message()).toContain('数据库密钥无效')
-    await dialog.dismiss()
+    await fixture.page.getByRole('button', { name: '连接数据库' }).click()
+    await expect(fixture.page.getByText('数据库密钥无效')).toBeVisible()

    await expect(keyInput).toBeVisible()
    await keyInput.fill('a'.repeat(64))
@@ -40,6 +35,46 @@ test('KEY-01 KEY-02 invalid key remains recoverable and valid key enters the app
  }
 })

+test('P0-01 an invalid directory can be corrected and retried without restarting', async () => {
+  test.skip(process.platform !== 'win32', 'Manual database directory editing is Windows-only')
+  const fixture = await launchTestApp({ mode: 'disconnected' })
+  try {
+    await fixture.page.getByRole('tab', { name: /高级用户/ }).click()
+    await fixture.page.getByLabel('数据库密钥').fill('a'.repeat(64))
+    await fixture.page.getByLabel('微信数据目录').fill('Z:\\missing-wechat-data')
+    await fixture.page.getByRole('button', { name: '连接数据库' }).click()
+
+    await expect(fixture.page.getByText('微信数据目录不存在，请重新选择目录')).toBeVisible()
+    await expect(fixture.page.getByLabel('微信数据目录')).toBeEditable()
+    await expect(fixture.page.getByRole('button', { name: '选择目录' })).toBeEnabled()
+
+    await fixture.page.getByRole('button', { name: '选择目录' }).click()
+    await expect(fixture.page.getByLabel('微信数据目录')).toHaveValue('fixture-account')
+    await fixture.page.getByRole('button', { name: '连接数据库' }).click()
+    await expect(fixture.page.getByRole('navigation', { name: '一级导航' })).toBeVisible()
+  } finally {
+    await fixture.close()
+  }
+})
+
+test('P2-01 P2-02 guided connection exposes safe diagnostics and completes all stages', async () => {
+  const fixture = await launchTestApp({ mode: 'disconnected' })
+  try {
+    await expect(fixture.page.getByText('4.1.9.57')).toBeVisible()
+    await expect(fixture.page.getByText('微信 4.x（WCDB）')).toBeVisible()
+    await expect(fixture.page.getByRole('button', { name: '复制脱敏诊断摘要' })).toBeEnabled()
+
+    await fixture.page.getByRole('button', { name: '检查完成，继续' }).click()
+    await fixture.page.getByRole('button', { name: '我已准备好' }).click()
+    await fixture.page.getByRole('button', { name: '开始准备连接组件' }).click()
+    await expect(fixture.page.getByRole('button', { name: '微信已登录，验证连接' })).toBeEnabled()
+    await fixture.page.getByRole('button', { name: '微信已登录，验证连接' }).click()
+    await expect(fixture.page.getByRole('navigation', { name: '一级导航' })).toBeVisible()
+  } finally {
+    await fixture.close()
+  }
+})
+
 test('KEY-03 changing one key does not invalidate archive data or unrelated settings', async () => {
  const fixture = await launchTestApp()
  try {
@@ -188,6 +223,7 @@ test('REPORT-01 REPORT-02 generates a fixed report with non-empty local assets',
    await fixture.page.getByRole('button', { name: '开始生成日报' }).click()
    await expect(fixture.page.getByRole('heading', { name: '生成群聊日报' })).toBeVisible()
    await fixture.page.locator('.report-source-item').filter({ hasText: '产品测试群' }).click()
+    await fixture.page.getByRole('button', { name: '近 7 天' }).click()
    const generate = fixture.page.getByRole('button', { name: '开始生成日报' })
    await expect(generate).toBeEnabled()
    await generate.click()
@@ -218,6 +254,7 @@ test('REPORT-03 report failure is retryable and leaves other pages usable', asyn
    await fixture.page.getByRole('button', { name: '日报' }).click()
    await fixture.page.getByRole('button', { name: '开始生成日报' }).click()
    await fixture.page.locator('.report-source-item').filter({ hasText: '产品测试群' }).click()
+    await fixture.page.getByRole('button', { name: '近 7 天' }).click()
    await fixture.page.getByRole('button', { name: '开始生成日报' }).click()
    await expect(fixture.page.getByText(/本地假服务错误 401/).first()).toBeVisible()
    await expect(fixture.page.getByRole('button', { name: '重试' })).toBeEnabled()
@@ -102,7 +102,7 @@ handle('key:getSavedDbKey', () => ({
  saved: Boolean(savedKey),
  encryptionAvailable: true
 }))
-handle('key:saveDbKey', (key) => {
+handle('key:saveDbKey', (_accountRoot, key) => {
  savedKey = String(key || '')
  return { success: true, key: savedKey, saved: true, encryptionAvailable: true }
 })
@@ -112,6 +112,12 @@ handle('key:clearSavedDbKey', () => {
 })
 handle('key:getEnvironment', () => ({
  platform: process.platform,
+  osVersion: process.platform === 'win32' ? 'Windows fixture' : 'macOS fixture',
+  appVersion: 'v2.1.6',
+  wechatVersion: '4.1.9.57',
+  dataStructureVersion: settings.dbRoot === 'fixture-account' ? '微信 4.x（WCDB）' : '未检测到',
+  dataDirectoryDetected: settings.dbRoot === 'fixture-account',
+  diagnosticSummary: 'WechatExplorer: v2.1.6\n数据目录: 已检测到',
  autoDetectSupported: true,
  wechatRunning: true,
  accountIdentified: connected,
@@ -128,12 +134,22 @@ handle('key:autoGetImageKey', () => ({
  verified: true
 }))

-handle('db:init', (key) => {
+handle('db:init', (key, accountRoot) => {
+  if (settings.dbRoot === 'Z:\\missing-wechat-data') {
+    connected = false
+    return {
+      success: false,
+      code: 'ROOT_UNAVAILABLE',
+      error: '微信数据目录不存在，请重新选择目录',
+      monitoring: false
+    }
+  }
  if (key !== VALID_KEY) {
    connected = false
    return { success: false, error: '数据库密钥无效', monitoring: false }
  }
  connected = true
+  settings.dbRoot = accountRoot || settings.dbRoot
  return { success: true, monitoring: true }
 })
 handle('db:testConnection', (key) =>
@@ -339,6 +355,29 @@ handle('image:getStatus', () => ({
    ])
  )
 }))
+handle('settings:selectDbRoot', () => ({ canceled: false, path: 'fixture-account' }))
+handle('accounts:discover', (inputPath) =>
+  inputPath === 'Z:\\missing-wechat-data'
+    ? { success: false, accounts: [], error: '微信数据目录不存在，请重新选择目录' }
+    : {
+        success: true,
+        inputKind: 'account',
+        preselectedAccountId: 'fixture-account-id',
+        accounts: [
+          {
+            id: 'fixture-account-id',
+            accountRoot: inputPath || 'fixture-account',
+            directoryName: 'fixture-account',
+            wxid: fixture.self.wxid,
+            nickname: fixture.self.nickname,
+            avatar: fixture.self.avatar,
+            hasSavedDbKey: Boolean(savedKey),
+            loginStatus: connected ? 'current' : 'unknown',
+            selectedByInput: true
+          }
+        ]
+      }
+)
 handle('agent-hub:getStatus', () => ({ state: 'disconnected', connected: false }))
 handle('agent-hub:getLogs', () => [])
 handle('app-update:getState', () => ({ status: 'idle', currentVersion: '2.1.6' }))
@@ -347,7 +386,6 @@ for (const channel of [
  'export:start',
  'export:cancel',
  'export:reveal',
-  'settings:selectDbRoot',
  'settings:openAccountRoot',
  'db:reopenWithRoot',
  'api:skillStatus',
@@ -0,0 +1,173 @@
+import { dirname, join } from 'path'
+import { mkdtempSync, readFileSync, rmSync, writeFileSync } from 'fs'
+import { tmpdir } from 'os'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import type { Message } from '../../src/shared/types'
+
+const state = vi.hoisted(() => ({
+  documents: '',
+  videoPath: '',
+  messages: [] as Message[],
+  imageLookups: [] as { allowThumbnail?: boolean; preferThumbnail?: boolean }[]
+}))
+
+vi.mock('electron', () => ({
+  app: { getPath: () => state.documents },
+  shell: { showItemInFolder: vi.fn() },
+  BrowserWindow: class {}
+}))
+vi.mock('../../src/main/services/chat-service', () => ({
+  listMessages: () => structuredClone(state.messages),
+  getChatDb: () => ({ getWcdb4Client: () => ({}) }),
+  getContactAvatars: () => ({})
+}))
+vi.mock('../../src/main/services/image-key-config-service', () => ({
+  ImageKeyConfigService: class {
+    getConfig(): { aesKey: string; xorKey: string } {
+      return { aesKey: '0123456789abcdef', xorKey: '0x40' }
+    }
+  }
+}))
+vi.mock('../../src/main/voice-service', () => ({
+  VoiceService: class {
+    async resolveVoice(
+      _sessionId: string,
+      localId: number
+    ): Promise<{ success: boolean; data?: string; error?: string }> {
+      return localId === 1
+        ? {
+            success: true,
+            data: 'UklGRiQAAABXQVZFZm10IBAAAAABAAEAQB8AAEAfAAABAAgAZGF0YQAAAAA='
+          }
+        : { success: false, error: '本地未找到语音数据' }
+    }
+  }
+}))
+vi.mock('../../src/main/image-decrypt-service', () => ({
+  ImageDecryptService: class {
+    findImageFile(
+      _md5: string,
+      _datName: string,
+      options: { allowThumbnail?: boolean; preferThumbnail?: boolean }
+    ): string {
+      state.imageLookups.push(options)
+      return 'fixture-original.dat'
+    }
+    decryptImageToBase64WithFallback(): { data: string; filePath: string } {
+      return {
+        data: 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAusB9Y9ZQmcAAAAASUVORK5CYII=',
+        filePath: 'fixture-original.dat'
+      }
+    }
+    isThumbnailFile(): boolean {
+      return false
+    }
+  }
+}))
+vi.mock('../../src/main/video-asset-service', () => ({
+  VideoAssetService: class {
+    resolve(): { success: boolean; url: string } {
+      return { success: true, url: 'wxe-media://local/fixture-video' }
+    }
+    pathForUrl(): string {
+      return state.videoPath
+    }
+  }
+}))
+vi.mock('../../src/main/sticker-service', () => ({
+  StickerService: class {}
+}))
+
+const message = (overrides: Partial<Message>): Message => ({
+  id: 'fixture',
+  from: 'fixture',
+  type: '普通文本',
+  datetime: '2026-08-01 10:00:00',
+  content: '',
+  isSender: false,
+  createTime: 1_785_549_600,
+  ...overrides
+})
+
+describe('media export flow', () => {
+  beforeEach(() => {
+    state.documents = mkdtempSync(join(tmpdir(), 'wxe-export-fixture-'))
+    state.videoPath = join(state.documents, 'fixture.mp4')
+    writeFileSync(
+      state.videoPath,
+      Buffer.from('000000186674797069736f6d0000020069736f6d69736f32', 'hex')
+    )
+    state.imageLookups = []
+    state.messages = [
+      message({
+        id: 'voice-ok',
+        type: '语音',
+        sessionId: 'fixture-session',
+        localId: 1,
+        contentData: { type: 'voice', duration: 1 }
+      }),
+      message({
+        id: 'voice-missing',
+        type: '语音',
+        sessionId: 'fixture-session',
+        localId: 2,
+        contentData: { type: 'voice', duration: 1 }
+      }),
+      message({
+        id: 'image',
+        type: '图片',
+        sessionId: 'fixture-session',
+        contentData: { type: 'image', md5: 'a'.repeat(32), datName: 'fixture.dat' }
+      }),
+      message({
+        id: 'video',
+        type: '视频',
+        contentData: { type: 'video', md5: 'b'.repeat(32) }
+      })
+    ]
+  })
+
+  afterEach(() => rmSync(state.documents, { recursive: true, force: true }))
+
+  it('writes playable relative assets, keeps failures, and requests the original image first', async () => {
+    const { runExport } = await import('../../src/main/export-service')
+    const progress: unknown[] = []
+    const win = {
+      isDestroyed: () => false,
+      webContents: { send: (...args: unknown[]) => progress.push(args) }
+    }
+    const result = await runExport(
+      {
+        jobId: 'fixture-export',
+        userMd5: 'fixture-user',
+        name: '脱敏会话',
+        format: 'html',
+        outputName: 'fixture',
+        kinds: ['voice', 'image', 'video'],
+        includeMedia: true,
+        preferOriginal: true,
+        fallbackThumbnail: true,
+        keepMissing: true
+      },
+      win as never
+    )
+
+    expect(result.success).toBe(true)
+    const html = readFileSync(result.outputPath!, 'utf8')
+    const outputDir = dirname(result.outputPath!)
+    expect(readFileSync(join(outputDir, 'voices/voice_1_1.wav')).subarray(0, 4).toString()).toBe(
+      'RIFF'
+    )
+    expect(readFileSync(join(outputDir, 'media/video_4.mp4')).subarray(4, 8).toString()).toBe(
+      'ftyp'
+    )
+    expect(html).toContain('src="voices/voice_1_1.wav"')
+    expect(html).toContain('src="media/video_4.mp4"')
+    expect(html).toContain('语音文件缺失：本地未找到语音数据')
+    expect(state.imageLookups[0]).toMatchObject({
+      allowThumbnail: false,
+      preferThumbnail: false
+    })
+    expect(progress.length).toBeGreaterThan(0)
+  })
+})
@@ -0,0 +1,69 @@
+import fs from 'fs-extra'
+import os from 'os'
+import path from 'path'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+const mocked = vi.hoisted(() => ({
+  userData: `${process.env.TEMP || process.env.TMP || '.'}/wxe-account-discovery-tests`
+}))
+
+vi.mock('electron', () => ({
+  app: { getPath: () => mocked.userData }
+}))
+
+import { discoverAccounts } from '../../src/main/services/account-discovery'
+
+describe('account discovery', () => {
+  let root: string
+  const keyStore = {
+    getStatus: vi.fn(async (accountRoot: string) => ({
+      saved: accountRoot.endsWith('account-b'),
+      encryptionAvailable: true
+    }))
+  }
+
+  beforeEach(async () => {
+    root = await fs.mkdtemp(path.join(os.tmpdir(), 'wxe-accounts-'))
+    await Promise.all(
+      ['account-a', 'account-b', 'account-c'].map((name) =>
+        fs.ensureDir(path.join(root, name, 'db_storage'))
+      )
+    )
+    await fs.ensureDir(path.join(root, 'Backup'))
+  })
+
+  afterEach(async () => {
+    await fs.remove(root)
+    await fs.remove(mocked.userData)
+  })
+
+  it('rejects an invalid Backup directory without continuing', async () => {
+    const result = await discoverAccounts(path.join(root, 'Backup'), keyStore as never)
+    expect(result.success).toBe(false)
+    expect(result.accounts).toEqual([])
+  })
+
+  it('lists every direct account and never preselects one from a root directory', async () => {
+    const result = await discoverAccounts(root, keyStore as never)
+    expect(result.success).toBe(true)
+    expect(result.accounts.map((account) => account.directoryName).sort()).toEqual([
+      'account-a',
+      'account-b',
+      'account-c'
+    ])
+    expect(result.preselectedAccountId).toBeUndefined()
+    expect(
+      result.accounts.find((account) => account.directoryName === 'account-b')?.hasSavedDbKey
+    ).toBe(true)
+  })
+
+  it('preselects a directly selected account directory while retaining its card', async () => {
+    const accountRoot = path.join(root, 'account-c')
+    const result = await discoverAccounts(accountRoot, keyStore as never)
+    expect(result.success).toBe(true)
+    expect(result.accounts).toHaveLength(1)
+    expect(result.accounts[0].accountRoot).toBe(accountRoot)
+    expect(result.preselectedAccountId).toBe(result.accounts[0].id)
+    expect(result.accounts[0].selectedByInput).toBe(true)
+  })
+})
@@ -0,0 +1,26 @@
+import { describe, expect, it } from 'vitest'
+import { buildSafeDiagnosticSummary } from '../../src/shared/connection-diagnostics'
+
+describe('connection diagnostics', () => {
+  it('contains useful versions and readiness without secrets or full account paths', () => {
+    const summary = buildSafeDiagnosticSummary({
+      platform: 'win32',
+      osVersion: 'Windows 11 fixture',
+      appVersion: 'v2.1.6',
+      wechatVersion: '4.1.9.57',
+      dataStructureVersion: '微信 4.x（WCDB）',
+      dataDirectoryDetected: true,
+      autoDetectSupported: true,
+      wechatRunning: true,
+      accountIdentified: true,
+      dbConnected: false,
+      encryptionAvailable: true
+    })
+
+    expect(summary).toContain('WechatExplorer: v2.1.6')
+    expect(summary).toContain('微信客户端: 4.1.9.57')
+    expect(summary).not.toContain('0123456789abcdef')
+    expect(summary).not.toContain('C:\\Users\\fixture\\xwechat_files\\wxid_secret')
+    expect(summary).not.toContain('wxid_')
+  })
+})
@@ -0,0 +1,62 @@
+import { describe, expect, it } from 'vitest'
+import { renderExportPage } from '../../src/main/export-html-template'
+import { getImageExportAttempts } from '../../src/shared/export-media'
+import type { Message } from '../../src/shared/types'
+
+const baseMessage = (overrides: Partial<Message>): Message => ({
+  id: 'fixture-message',
+  from: 'fixture',
+  type: '文本',
+  datetime: '2026-08-01 10:00:00',
+  content: '',
+  isSender: false,
+  ...overrides
+})
+
+describe('export media', () => {
+  it('always attempts the original before an explicitly enabled thumbnail fallback', () => {
+    const first = getImageExportAttempts({ preferOriginal: true, fallbackThumbnail: true })
+    const repeated = getImageExportAttempts({ preferOriginal: true, fallbackThumbnail: true })
+
+    expect(first).toEqual([
+      { allowThumbnail: false, preferThumbnail: false, fallback: false },
+      { allowThumbnail: true, preferThumbnail: true, fallback: true }
+    ])
+    expect(repeated).toEqual(first)
+  })
+
+  it('renders movable relative audio and video assets plus accurate missing-media details', () => {
+    const html = renderExportPage('脱敏导出', [
+      baseMessage({ id: 'voice', type: '语音', voiceDataUrl: 'voices/voice_1.wav' }),
+      baseMessage({
+        id: 'video',
+        type: '视频',
+        exportMediaType: 'video',
+        exportMediaUrl: 'media/video_2.mp4'
+      }),
+      baseMessage({
+        id: 'missing',
+        type: '语音',
+        exportMediaError: '语音文件缺失：本地未找到语音数据'
+      })
+    ])
+
+    expect(html).toContain(
+      'audio class="audio" controls preload="metadata" src="voices/voice_1.wav"'
+    )
+    expect(html).toContain('video class="media-image" controls src="media/video_2.mp4"')
+    expect(html).toContain('语音文件缺失：本地未找到语音数据')
+    expect(html).not.toMatch(/(?:src|href)="[A-Za-z]:\\/)
+  })
+
+  it('renders explicit and keyboard-accessible lightbox closing controls', () => {
+    const html = renderExportPage('图片预览', [
+      baseMessage({ id: 'image', type: '图片', exportMediaUrl: 'media/image.jpg' })
+    ])
+
+    expect(html).toContain('aria-label="关闭图片预览"')
+    expect(html).toContain("closeButton.addEventListener('click',closeLightbox)")
+    expect(html).toContain('if(event.target===box)closeLightbox()')
+    expect(html).toContain("if(event.key==='Escape')closeLightbox()")
+  })
+})
@@ -20,4 +20,14 @@ describe('message pagination', () => {
    )
    expect(merged.map((message) => message.id)).toEqual(['oldest', 'overlap', 'latest'])
  })
+
+  it('keeps cross-year pages continuous through the earliest fixture record', () => {
+    const page2025 = [makeMessage('2025', 1_735_689_600), makeMessage('2026', 1_767_225_600)]
+    const page2017 = [makeMessage('2017', 1_483_228_800), makeMessage('2025', 1_735_689_600)]
+
+    const merged = mergeMessagePages(page2017, page2025)
+
+    expect(merged.map((message) => message.id)).toEqual(['2017', '2025', '2026'])
+    expect(new Set(merged.map((message) => message.id)).size).toBe(merged.length)
+  })
 })
@@ -0,0 +1,45 @@
+import { describe, expect, it, vi } from 'vitest'
+import { Wcdb4Client, type Wcdb4Message } from '../../src/main/wcdb4-client'
+
+const message = (id: string, year: number): Wcdb4Message => ({
+  mesLocalID: id,
+  serverId: `server-${id}`,
+  mesDes: 0,
+  messageType: '1',
+  msgCreateTime: String(Math.floor(Date.UTC(year, 0, 1) / 1000)),
+  msgContent: `fixture-${year}`,
+  raw: {}
+})
+
+describe('WCDB message shard pagination', () => {
+  it('merges cursor and all-store rows for a bounded cross-year page', async () => {
+    const cursor = vi.fn(async () => [message('2025', 2025)])
+    const tableScan = vi.fn(async () => [message('2017', 2017), message('2025', 2025)])
+    const client = Object.assign(Object.create(Wcdb4Client.prototype), {
+      wcdbGetMessageTableStats: vi.fn(),
+      wcdbExecQuery: vi.fn(),
+      getMessagesByCursorAsync: cursor,
+      getMessagesByTableScanAsync: tableScan
+    }) as Wcdb4Client
+
+    const result = await client.getMessagesAsync(
+      'fixture@chatroom',
+      undefined,
+      Math.floor(Date.UTC(2026, 0, 1) / 1000),
+      { limit: 20 }
+    )
+
+    expect(tableScan).toHaveBeenCalledOnce()
+    expect(result.map((item) => item.msgContent)).toEqual(['fixture-2017', 'fixture-2025'])
+  })
+
+  it('reports an unsupported shard query instead of claiming history ended', async () => {
+    const client = Object.assign(Object.create(Wcdb4Client.prototype), {
+      getMessagesByCursorAsync: vi.fn(async () => [])
+    }) as Wcdb4Client
+
+    await expect(
+      client.getMessagesAsync('fixture@chatroom', undefined, 1_767_225_600, { limit: 20 })
+    ).rejects.toThrow('无法检查历史消息分片')
+  })
+})