OpenCode 2 publishes its CLI as @opencode/cli (opencode-ai stops at
1.19.x), so install that package and pin it to 2.0.32.
Also fix what the v2 migration invalidates:
- renovate.json: track @opencode/cli instead of opencode-ai, otherwise
the pin is never bumped.
- opencode-attach: `opencode attach` no longer exists in v2. Point the
client at the server with `--server <url>` instead (appended after a
subcommand when one is given); auth still comes from
OPENCODE_SERVER_PASSWORD / OPENCODE_PASSWORD.
- README/AGENTS: v2 package name, entrypoint, serve defaults, API
surface (/global/health is gone, everything lives under authenticated
/api/*), and removal of OPENCODE_SERVER_USERNAME (the username is
always `opencode` in v2).
The entrypoint stays ["opencode"] on purpose: existing deployments pass
`serve ...` at runtime, and OpenCode 2 is invoked the same way.
OpenCode Cabillot