The plugins docs advertise `omp list`/`omp remove` as top-level commands,
but only `omp install` is registered. `resolveCliArgv` rewrote any
unregistered first-arg to `launch`, so `omp list` silently started an
interactive agent session with "list" as the LLM prompt instead of
managing plugins.
Reserve the bare, documented-but-unregistered plugin verbs `list` and
`remove` with a helpful hint pointing at the real `omp plugin list` /
`omp plugin uninstall <name>` commands (same `extensions` mechanism /
same class as the `install` leak fixed in #1496/#1498). Multi-word
prompts that merely begin with those words still route to `launch`, so
genuine prompts are unaffected.
Fixes#2935
can1357