Feature request: /plugin list should show plugin versions

Feature Request

/plugin list currently shows plugin names and source paths but not version numbers.

Current behavior

┌─────────────────────────┬─────────────────────────────────────────────────────────┐
│         Plugin          │                         Source                          │
├─────────────────────────┼─────────────────────────────────────────────────────────┤
│ review-loop-marketplace │ ~/.claude/plugins/marketplaces/review-loop-marketplace/ │
└─────────────────────────┴─────────────────────────────────────────────────────────┘

Expected behavior

┌─────────────────────────┬─────────┬─────────────────────────────────────────────────────────┐
│         Plugin          │ Version │                         Source                          │
├─────────────────────────┼─────────┼─────────────────────────────────────────────────────────┤
│ review-loop-marketplace │ 2.0.0   │ ~/.claude/plugins/marketplaces/review-loop-marketplace/ │
└─────────────────────────┴─────────┴─────────────────────────────────────────────────────────┘

Why

After running /plugin update or /reload-plugins, there's no way to confirm which version is actually loaded in the current session. The version is in plugin.json but users shouldn't have to cat that file manually. This is especially important because Claude Code caches plugins at session start, so the loaded version may differ from what's on disk.