Issue for this PR

Closes #N/A

Type of change

• Bug fix
• New feature
• Refactor / code improvement
• Documentation

What does this PR do?

Add @ulthon/ul-opencode-event to the Plugins table in packages/web/src/content/docs/ecosystem.mdx.

This is a community notification plugin for OpenCode that provides:

• Multi-channel notifications — SMTP email, DingTalk bot, Feishu bot alerts on session lifecycle events (idle, error, permission, question, etc.)
• Multi-level token analytics — tracks token usage at message / session / total / project levels, with automatic session cache and DB preload for recovery across restarts
• Global + project-level config merge, i18n templates (zh/en), built-in CLI test tool

npm: https://www.npmjs.com/package/@ulthon/ul-opencode-event

How did you verify your code works?

Verified the Markdown table row renders correctly. The plugin is published on npm (npm view @ulthon/ul-opencode-event) and the Gitee repo is publicly accessible.

Screenshots / recordings

N/A (documentation change only)

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR