Add stream_hub plugins

[yzbf-lin]

Summary

• Add backend plugin submodule: https://github.com/yzbf-lin/stream_hub
• Add frontend plugin submodule: https://github.com/yzbf-lin/stream_hub_ui
• Regenerate plugin marketplace data for both plugins

Validation

• pnpm run generate
• pnpm run validate

Validation result: 19 plugins passed, 0 failed.

[github-actions]

Plugin TOML Validation Report

Status: ✅ All Passed

✅ stream_hub

Field	Value	Status
summary	流式事件中心	✅
version	0.0.1	✅
description	统一 Socket.IO 事件通道、订阅、日志 tail 与前端消费协议	✅
author	pd-qa-backend	✅
icon	-	➖
tags	task	✅
database	mysql	✅

✅ stream_hub_ui

Field	Value	Status
summary	流式事件中心	✅
version	0.0.1	✅
description	统一事件通道、日志 tail 与日志文件查看页	✅
author	pd-qa-backend	✅
icon	-	➖
tags	task, other	✅
database	-	➖

[wu-clan]

可以根据 fba skills 优化下插件 README：https://github.com/fastapi-practices/skills/blob/master/skills/fastapi-best-architecture/references/plugin.md#plugin-readme-convention