chore:add group task board plugin source

[Wyh-max-star]

Summary

This PR adds a third-party plugin source entry for group_task_board in plugins/source.json.

The plugin source code is maintained in a separate repository:

https://github.com/Wyh-max-star/cowagent-plugin-group-task-board

This PR only registers the plugin source URL and description. It does not add the plugin implementation code into the CowAgent main repository.

Plugin Description

group_task_board is a lightweight group chat task management plugin for CowAgent.

In group chat scenarios, task assignments are often mixed with normal conversations and can easily be missed. This plugin helps users create, view, update, and complete simple tasks directly in group conversations.

It is suitable for scenarios such as:

• course project collaboration
• team task assignment
• meeting follow-up tasks
• group reminders
• lightweight task tracking in chat

Main Features

• Create task records from group chat commands
• View the current task list
• Mark tasks as completed
• Check task status
• Provide basic help information for task commands

Usage

After installing the plugin, users can manage tasks with commands such as:

#task add 张三 明天之前整理会议纪要
#task list
#task done 1
#task status
#task help

Example 1: create a task

User:
#task add 李四 周五前完成接口测试

CowAgent:
已创建任务 #1
负责人：李四
任务内容：完成接口测试
截止时间：周五前
状态：待完成

Example 2: view task list

User:
#task list

CowAgent:
当前任务列表：
#1 李四｜完成接口测试｜周五前｜待完成
#2 张三｜整理会议纪要｜明天前｜进行中

Example 3: mark a task as completed

User:
#task done 1

CowAgent:
任务 #1 已标记为完成。

Changes in This PR

• Add group_task_board to plugins/source.json
• Add the external plugin repository URL
• Add a short description for the plugin

Notes

CowAgent's plugins/source.json uses external plugin repository URLs and descriptions to register plugins. This PR follows that format and only adds the plugin source entry.

The plugin implementation is maintained here:

https://github.com/Wyh-max-star/cowagent-plugin-group-task-board

[zhayujie]

Thanks for the contribution. One small thing: the repo has committed pycache/. These are generated files that shouldn't be version-controlled — adding a .gitignore would keep the repo clean

[Wyh-max-star]

Thanks for the review and for merging the PR!

I have updated the plugin repository by adding a .gitignore file and removing the committed __pycache__ / Python cache files from version control.

Plugin repository:
https://github.com/Wyh-max-star/cowagent-plugin-group-task-board