Extension marked active but pm-graph command path is not exposed #27

While testing pm-web against the current pm CLI runtime, the bundled pm-graph extension installs and appears active in pm extension explore --project --json, but invoking the registered command fails.

Evidence from a fresh pm-web project:

pm extension explore --project --json
# details.extensions[0]: name=pm-graph, active=true, enabled=true

pm pm-graph export --json
# error: pm does not expose command path "pm-graph" in current runtime configuration.

The extension registers commands named pm-graph ping, pm-graph export, pm-graph cypher, and pm-graph sync. pm-web can fall back to its built-in graph exporter, but the extension lifecycle reports active while its command path is unavailable.

Expected: active project extensions that register command paths should expose those command paths in the same runtime, or extension explore should surface an activation/registration failure.