`graphify opencode install` wrote a plugin with only a named export, the
OpenCode 1 shape. OpenCode 2 rejects it ("Plugin must export a default
definition with an id and an effect or setup function") and reads the bare
path registered in opencode.json as an npm package name, so it fails twice
on every start.
The plugin is now one default export with `id`, `setup()` for OpenCode 2
and `server()` for OpenCode 1 (1.3.4 and later). The installer no longer
writes the opencode.json entry, because both runtimes discover
.opencode/plugins/ on their own, and it removes the entry older releases
wrote.
OpenCode loads .opencode/plugins/ from the project and from every directory
above it, and OpenCode 2 fails a second plugin with the same id ("Duplicate
plugin ID"). An install in ~ and one in a project are both normal, so the id
carries the file's location and the copies share one record of who was
reminded: both load, and a command still gets a single reminder.
Upgrading graphify does not touch a plugin already on disk. So the CLI now
rewrites an old-shape plugin in the working directory or in the home
directory on its next run, and drops the stale entry there, next to the
stale-skill refresh from #1805. It does so only when the `opencode` on PATH
reports 1.3.4 or later, because older OpenCode 1 releases cannot load the
new plugin and the one they have still works. The rewrite takes the same
per-directory lock as the skill refresh and replaces both files atomically,
because OpenCode watches them. GRAPHIFY_NO_AUTO_REFRESH=1 turns it off.
(cherry picked from commit 0e539e1f7a)
