docs: add local-code-opencode-plugin to ecosystem

[wi202im]

Issue for this PR

Closes N/A

Type of change

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

What does this PR do?

Adds local-code-opencode-plugin to the Ecosystem plugins table.

The plugin is published on npm and injects git-based handoff context when switching models in OpenCode.

How did you verify your code works?

Verified the MDX table row locally by checking the diff. This PR only changes the ecosystem documentation list.

Screenshots / recordings

N/A

Checklist

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

[github-actions]

Hey! Your PR title Add local-code-opencode-plugin to ecosystem doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍