## Core
### Bugfixes
- OpenCode 1 now stays on the 1.x release line: update checks use only the npm `opencode-ai` latest version, so 1.x installs are never offered a 2.x build as a regular update.
- Upgrading to OpenCode 2 remains a separate, explicit choice through the 2.0 offer in `/update` or `opencode upgrade --major`.
- Fix upgrades for installs managed by yarn.
- Skip 1.x updates for Homebrew Core installs, which now track OpenCode 2, and check tap and Chocolatey availability before offering an update.
- The install script refuses to install 2.x versions.