fix(plugin): load local toolkit and expose status tool

FIXME.md

@@ -3,13 +3,13 @@
 - [ ] The installer deliberately refuses projects with both
   `opencode.json` and `.opencode/opencode.json`. Decide whether safe support for
   multi-layer config is worth implementing after studying V2 merge behavior.
-- [ ] The plugin passes V2 contract tests and the package tarball installs, but
-  `opencode api --standalone get /api/plugin` returned an empty plugin list for
-  both the installed package and a minimal local smoke plugin. Diagnose whether
-  this reflects loading, API reporting, or configuration before claiming the
-  custom tool is active.
-- [ ] `opencode debug agents` discovers the three installed toolkit agents from
-  the tarball, but this does not establish that plugin hooks/tools load.
+- [x] The installer previously registered the unpublished npm package name,
+  which made OpenCode attempt a registry download and fail with 404. It now
+  registers the local package directory. The package root provides `index.js`
+  because configured local plugin paths must be directories with an entrypoint.
+- [x] The namespaced tool now opts into Code Mode. OpenCode 2.0.24 loaded the
+  installed tarball and executed `toolkit_project_status` through a local mock
+  OpenAI-compatible endpoint without external model usage.
 - [ ] Provider-backed workflows (agent delegation and actual skill invocation)
   have not been tested; they require configured credentials and explicit
   approval of any model usage.