Graduate 2.0.0-rc.1 to stable. Bump version across package, plugin,
marketplace, OpenCode, agent metadata, VERSION, and all localized docs.
Add 2.0.0 release notes + README sections (en/zh/pt-BR/tr), CHANGELOG
entry, and the ECC community Discord bot (dependency-free gateway client
+ guild command registrar). Update copilot-support and release-surface
tests for the sponsored-review migration and the 2.0.0 surface.
The OpenCode sub-package had stale 1.0.0 versions in package.json,
index.ts VERSION export, and package-lock.json while the main package
is at 1.4.1. Updated all three to match.