test(layout): add comprehensive tests for HLCRF layout system
Add tests for the HLCRF (Header-Left-Content-Right-Footer) layout system
covering all required functionality:
- Layout variant parsing (C, HC, HCF, LC, CR, LCR, HLCRF, etc.)
- Self-documenting ID system (H-0, C-R-2, data-block, data-slot)
- Nested layout rendering with correct path propagation
- Slot rendering with multiple content types (string, Htmlable, closures)
- Alias methods (addHeader, addLeft, addContent, addRight, addFooter)
- Attributes and CSS class management
- Semantic HTML structure (header, aside, main, footer elements)
- Real-world layout patterns (admin dashboard, docs site, email client)
- Edge cases and boundary conditions
80+ tests covering the complete HLCRF layout system.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>