TSRX feature stress tests

One page per TSRX language feature, each backed by a `.tsrx` component.

• Statement container @{ }
• Conditional @if / @else
• List rendering @for / @empty / key
• Switch @switch / @case / @default
• Error handling @try / @catch
• Lazy destructuring &{ }
• Scoped styles <style> + CSS vars + :global()
• Dynamic tag names <{Tag}>
• Hooks in branches hooks inside @if / @for