🔧 chore: enforce monorepo best practices with automated validation

Fix critical issues and add validation to prevent future violations:

**Fixes:**
- Remove turbo recursion in 5 app packages (infinite loop risk)
- Add "private": true to 11 packages (prevent accidental publishing)
- Rename @mana-core/nestjs-integration → @manacore/nestjs-integration
- Remove prepublishOnly scripts from 3 private packages

**New:**
- Add scripts/validate-monorepo.mjs with 4 critical checks
- Add validate:monorepo command to package.json
- Integrate validation into CI pipeline (.github/workflows/ci.yml)
- Document validation in CLAUDE.md

All 80 package.json files now pass validation ✅

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

apps/chat/package.json

@@ -4,6 +4,6 @@
 	"private": true,
 	"description": "Chat project - AI chat application with mobile, web and landing",
 	"scripts": {
-		"dev": "turbo run dev"
+		"dev": "pnpm run --filter=@chat/* --parallel dev"
 	}
 }