fix: 修复媒体导出与 HTML 聊天档案体验

- 修复打包版图片、语音解析不可用，内置 FFmpeg 与必要运行时依赖
- 修复 HTML 导出原图查找、缩略图回退及增量档案媒体解析问题
- 修复本人昵称在软件和 HTML 导出中显示为微信号的问题，并兼容旧档案昵称迁移
- 修复 HTML 语音播放器超出消息气泡的问题
- 优化 HTML 双向滚动加载，大量消息时最多渲染 240 条，避免页面卡顿
- 移除图片解密页面中手动配置 FFmpeg 的相关提示
- 补充图片解密、语音运行时、打包资源和 HTML 导出相关测试

tests/unit/chat-service.test.ts

@@ -2,6 +2,7 @@ import { afterEach, describe, expect, it, vi } from 'vitest'
 import type { WechatDb } from '../../src/main/wechat-db'
 import {
   closeChatDbForQuit,
+  getSelfAccountInfoAsync,
   isReady,
   listContactsAsync,
   setChatDb
@@ -42,6 +43,39 @@ describe('chat service contacts', () => {
     expect(contacts[0]?.m_nsNickName).toBe('测试群聊')
   })
 
+  it('hydrates the current account nickname before returning self info', async () => {
+    const session = { username: 'a969409112', nickname: 'a969409112' }
+    const client = {
+      getSessionsAsync: vi.fn(async () => {
+        session.nickname = '濑岛田井卫'
+        return [session]
+      }),
+      getAccountRoot: () => '/fixture/a969409112_d784',
+      getMyUsernameCandidates: () => ['a969409112'],
+      getUsernameByMd5: () => undefined,
+      md5: () => 'fixture-md5',
+      getMyAvatarUrl: () => undefined
+    }
+    const fakeDb = {
+      close: vi.fn(),
+      md5: () => 'fixture-md5',
+      getAllGroupContacts: () => ({}),
+      getUserList: () => [
+        {
+          m_nsUsrName: session.username,
+          nickname: session.nickname
+        }
+      ],
+      getWcdb4Client: () => client
+    } as unknown as WechatDb
+
+    setChatDb(fakeDb)
+    const info = await getSelfAccountInfoAsync()
+
+    expect(client.getSessionsAsync).toHaveBeenCalledWith({ hydrateDisplayNames: true })
+    expect(info).toMatchObject({ wxid: 'a969409112', nickname: '濑岛田井卫' })
+  })
+
   it('detaches the database immediately and awaits native cleanup on quit', async () => {
     let finishClose: ((value: boolean) => void) | undefined
     const closeAsync = vi.fn(