feat: Add Telegram voice message receiving support

[Copilot]

概述 / Overview

Implements Telegram voice message receiving. Adapter now captures voice messages via filters.VOICE, downloads OGG/Opus audio from Telegram API, and converts to platform_message.Voice components with base64 encoding for LLM processing.

实现电报语音消息接收。适配器现在通过 filters.VOICE 捕获语音消息，从 Telegram API 下载 OGG/Opus 音频，并转换为带有 base64 编码的 platform_message.Voice 组件供 LLM 处理。

Changes / 更改

File: src/langbot/pkg/platform/sources/telegram.py (+21 lines)

1. Message handler filter - Added filters.VOICE to capture voice messages

   MessageHandler(filters.TEXT | filters.COMMAND | filters.PHOTO | filters.VOICE, callback)

2. Voice processing in target2yiri() - Downloads voice file, extracts MIME type, encodes to base64:

   if message.voice:
       file = await message.voice.get_file()
       file_format = message.voice.mime_type or 'audio/ogg'
       async with aiohttp.ClientSession(trust_env=True) as session:
           async with session.get(file.file_path) as response:
               file_bytes = await response.read()
       message_components.append(
           platform_message.Voice(
               base64=f'data:{file_format};base64,{base64.b64encode(file_bytes).decode("utf-8")}',
               length=message.voice.duration,
           )
       )

Technical Notes / 技术说明

• Follows existing photo handling pattern for consistency
• Pipeline preprocessing already handles Voice components as file content
• Zero new dependencies; uses existing python-telegram-bot and aiohttp
• Works automatically without configuration changes

更改前后对比截图 / Screenshots

N/A - Backend adapter change, no UI modifications

不适用 - 后端适配器更改，无用户界面修改

检查清单 / Checklist

PR 作者完成 / For PR author

• 阅读仓库贡献指引了吗？ / Have you read the contribution guide?
• 与项目所有者沟通过了吗？ / Have you communicated with the project maintainer?
• 我确定已自行测试所作的更改，确保功能符合预期。 / I have tested the changes and ensured they work as expected.

项目维护者完成 / For project maintainer

• 相关 issues 链接了吗？ / Have you linked the related issues?
• 配置项写好了吗？迁移写好了吗？生效了吗？ / Have you written the configuration items? Have you written the migration? Has it taken effect?
• 依赖加到 pyproject.toml 和 core/bootutils/deps.py 了吗 / Have you added the dependencies to pyproject.toml and core/bootutils/deps.py?
• 文档编写了吗？ / Have you written the documentation?

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Feature]: Telegramm Voice Messages Recieving</issue_title>
<issue_description>### This is a?

New feature

Detailed description

Please add it asap . It’s very crucial part of build a really great telegram based chat bot . All other services like dify etc are supporting voice . I hope you could do it asap 🙏🏽</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Feature]: Telegramm Voice Messages Recieving #1942

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