v0.150.0: npm plugin sources and long-session performance

New features

- npm plugin sources - Plugin marketplace definitions can now reference plugins published as npm packages
- Quit confirmation - Desktop now asks for confirmation before quitting or closing would interrupt an active Droid session (app)

Improvements

- Long session performance - Improved chat performance in long sessions (app)
- MCP authentication page - Polished the MCP authentication success page
- Overdue invoice banner - Billing settings now show a banner when an invoice is overdue (app)

Bug fixes

- Rate limit reset display - Fixed the rate limit reset time shown for sub-hour resets