release: bump to v6.0.0-alpha.6

Bug Fixes:
- Fix manifestPath error in ide-config-manager causing installation failures
- Fix installer option display to show full labels instead of just values for single/multi-select
- Add conditional documentation installation - users can now opt out of installing docs

Improvements:
- Add install_user_docs configuration option (defaults to true)
- Improve config question display with descriptive labels for better UX
- Update CONTRIBUTING.md to remove references to non-existent 'next' branch

Maintenance:
- Closed 54 legacy v4 issues (older than 1 month) to maintain clean issue tracker

CONTRIBUTING.md

@@ -86,25 +86,13 @@ Please propose small, granular changes! For large or significant changes, discus
 
 ### Which Branch?
 
-**Submit to `next` branch** (most contributions):
-
-- ✨ New features or agents
-- 🎨 Enhancements to existing features
-- 📚 Documentation updates
-- ♻️ Code refactoring
-- ⚡ Performance improvements
-- 🧪 New tests
-- 🎁 New bmad modules
-
-**Submit to `main` branch** (critical only):
+**Submit PR's to `main` branch** (critical only):
 
 - 🚨 Critical bug fixes that break basic functionality
 - 🔒 Security patches
 - 📚 Fixing dangerously incorrect documentation
 - 🐛 Bugs preventing installation or basic usage
 
-**When in doubt, submit to `next`**. We'd rather test changes thoroughly before they hit stable.
-
 ### PR Size Guidelines
 
 - **Ideal PR size**: 200-400 lines of code changes

package.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://json.schemastore.org/package.json",
   "name": "bmad-method",
-  "version": "6.0.0-alpha.5",
+  "version": "6.0.0-alpha.6",
   "description": "Breakthrough Method of Agile AI-driven Development",
   "keywords": [
     "agile",