🔧 CRITICAL BUG FIX: Duplicate CorrelationIdMiddleware registration resolved

Fixed Issue:
- Duplicate middleware registration in UseEasyAuthCors() + UseEasyAuth()
- Potential startup conflicts when both methods used together
- Middleware responsibility clarity

Solution:
- Remove duplicate CorrelationIdMiddleware from UseEasyAuthCors()
- Clear documentation of middleware ownership
- Single responsibility: UseEasyAuth() owns CorrelationIdMiddleware

Quality Assurance:
- ✅ 176/176 unit tests passing
- ✅ No breaking changes to public API
- ✅ All v2.3.0 zero-config features preserved
- ✅ Immediate fix for potential conflicts

Upgrade from v2.3.0:
- No code changes required
- Automatic fix for middleware conflicts
- Enhanced reliability and stability