`omp marketplace add xyz` and the other documented `omp plugin <action>`
verbs (marketplace, discover, upgrade, uninstall, enable, disable) were
never registered top-level commands, so `resolveCliArgv` forwarded the
whole argv to `launch` as an LLM prompt. The #2935 guard only caught
bare single-word verbs, missing the multi-word documented grammar.
Extended `reservedTopLevelWordMessage` to hint at the real
`omp plugin <action>` command for these verbs when used bare, with a
marketplace sub-action, or with a `name@marketplace` plugin id, while
genuine prose prompts beginning with the same words still route to
`launch`.
Fixes#4845
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