Enhanced Marketplace Removal Cleanup

What: Removing a marketplace now automatically cleans up all references from settings files, preventing orphaned configuration entries.

How it works:

# When you remove a marketplace:
claude marketplace remove my-marketplace

# Now also removes:
# - extraKnownMarketplaces.my-marketplace from all settings files
# - All enabledPlugins entries like "plugin-name@my-marketplace"
# - Cleans userSettings, projectSettings, and localSettings

Details:

• Iterates through all settings files (user, project, local)
• Removes marketplace from extraKnownMarketplaces
• Removes all plugins associated with the marketplace from enabledPlugins
• Logs cleanup actions for each settings file
• Handles errors gracefully if settings write fails
• Evidence: Enhanced function ruA() at line 263832 (replaced suA() from v2.0.27); cleanup loop at lines 263842-263868