Discovered plugin .mcp.json stdio servers launched relative command/cwd
values against the session cwd instead of the plugin's config directory,
breaking bundled ChatGPT/Codex plugins (e.g. Computer Use) with ENOENT
when spawning ./... from an unrelated cwd.
The claude-plugins and omp-plugins providers now resolve relative cwd and
path-like command (./ or ../) against the .mcp.json directory via a shared
resolvePluginStdioPaths helper; bare executables such as npx are left
untouched so PATH lookup still works.
Fixes#5330
roboomp
6467a3119e