[Bug] Plugin UI misattributes user-installed plugins to org and overwrites via user local settings rather than removing plugin

Bug Description
Bug: /plugin UI mislabels user-installed plugins as "installed by your org" and provides no clean uninstall path

Environment: Claude Code 2.1.126, macOS, enterprise plan

What happened:

1. I installed the playwright plugin yesterday from Claude's official plugin marketplace (claude-plugins-official). It appeared under "user" plugins in the /plugin UI at install time.
2. Today, when uninstalling a Claude Marketplace plugin, /plugin showed it as "installed by your org, disable via user settings local override" — which is wrong. It is from claude-plugins-official (Anthropic's official marketplace), not from either of my org marketplaces.
3. There was no obvious uninstall affordance in /plugin — only enable/disable. Toggling disable wrote "playwright@claude-plugins-official": false into settings.local.json rather than removing the install.
4. To actually uninstall I had to manually:

• Delete ~/.claude/plugins/data/playwright-claude-plugins-official
• Delete ~/.claude/plugins/data/playwright-inline
• Delete ~/.claude/plugins/cache/claude-plugins-official/playwright
• Delete ~/.claude/plugins/marketplaces/claude-plugins-official/external_plugins/playwright
• Remove the enabledPlugins entries from settings.json and settings.local.json by hand

Expected:

• /plugin should correctly attribute user-installed plugins to the marketplace they came from, not say "installed by your org" when the source is claude-plugins-official.
• /plugin should expose an "Uninstall" action that removes the plugin from the filesystem AND cleans both settings files, not just toggle enabled:false.

Impact: Confusing — I thought my org had pushed playwright to me. And the disable-only path leaves a half-installed plugin and orphaned settings entries the user has to clean up manually.

Environment Info

• Platform: darwin
• Version: 2.1.126
• Feedback ID: ff7b3641-1fcd-4210-964a-21448a110d61

Errors

[{"error":"Error: Failed to delete keychain entry: security: SecKeychainSearchCopyNext: The specified item could not be found in the keychain.\n    at UEq (/$bunfs/root/src/entrypoints/cli.js:256:287901)\n    at async Q79 (/$bunfs/root/src/entrypoints/cli.js:409:898)\n    at async Dr6 (/$bunfs/root/src/entrypoints/cli.js:409:796)\n    at async S$_ (/$bunfs/root/src/entrypoints/cli.js:2744:2257)\n    at async MGH (/$bunfs/root/src/entrypoints/cli.js:2770:6041)\n    at async <anonymous> (/$bunfs/root/src/entrypoints/cli.js:2795:3410)\n    at processTicksAndRejections (native:7:39)","timestamp":"2026-05-02T11:49:36.923Z"}]