Node 20, installer improvements, agent improvements and Expansion Pack for game dev (#232)

* feat: add expansion pack installation system with game dev and infrastructure expansion packs

- Added expansion pack discovery and installation to BMAD installer
- Supports interactive and CLI installation of expansion packs
- Expansion pack files install to destination root (.bmad-core)
- Added game development expansion pack (.bmad-2d-phaser-game-dev)
  - Game designer, developer, and scrum master agents
  - Game-specific templates, tasks, workflows, and guidelines
  - Specialized for Phaser 3 + TypeScript development
- Added infrastructure devops expansion pack (.bmad-infrastructure-devops)
  - Platform engineering agent and infrastructure templates
- Expansion pack agents automatically integrate with IDE rules
- Added list:expansions command and --expansion-packs CLI option

🤖 Generated with Claude Code

Co-Authored-By: Claude <noreply@anthropic.com>

* alpha expansion packs and installer update to support installing expansion packs optionally

* node20

---------

Co-authored-by: Brian Madison <brianmadison@Brians-MacBook-Pro.local>
Co-authored-by: Claude <noreply@anthropic.com>

.roo/README.md

@@ -8,16 +8,7 @@ The `.roomodes` file defines all BMAD agents as custom modes using the proper `c
 
 ## Available Modes
 
-- **bmad-analyst** - Business Analyst
-- **bmad-architect** - Solution Architect
-- **bmad-bmad-master** - BMAD Master
-- **bmad-bmad-orchestrator** - BMAD Orchestrator
-- **bmad-dev** - Developer
-- **bmad-pm** - Product Manager
-- **bmad-po** - Product Owner
-- **bmad-qa** - QA Specialist
-- **bmad-sm** - Scrum Master
-- **bmad-ux-expert** - UX Expert
+
 
 ## Usage