docs(ecosystem): add opencode-session-id-plugin to the Plugins list

[hardes11]

What

Request to add opencode-session-id-plugin to the Ecosystem → Plugins list on https://opencode.ai/docs/ecosystem.

Why

opencode-session-id-plugin is a TUI plugin that displays the session ID beneath the title in the OpenCode sidebar — restored for stable-channel users, since upstream only shows this line on dev/edge builds (gated behind InstallationChannel !== "latest"). The sidebar_title slot is an intentional extension point, so this is a legitimate use of the plugin surface rather than a patch over upstream behavior.

Published to npm as opencode-session-id-plugin (latest 1.1.1).

• GitHub: https://github.com/hardes11/opencode-session-id-plugin
• npm: https://www.npmjs.com/package/opencode-session-id-plugin

Proposed row

| [opencode-session-id-plugin](https://github.com/hardes11/opencode-session-id-plugin) | Show the session ID beneath the title in the OpenCode sidebar |

Companion PR: #37673.

[github-actions]

This issue might be a duplicate of existing issues. Please check:

• docs(ecosystem): add opencode-session-id-plugin to the Plugins list #37676: Identical issue submitted by the same author with the same content and title ("docs(ecosystem): add opencode-session-id-plugin to the Plugins list")