Code Cleanup and Bump Dependencies

[Kaleidosium]

• Replace polling loop (setTimeout every 100ms) with yue:ready event listener for WASM initialization
• Wire up dead loadStub to s.onerror so the compiler UI degrades gracefully when WASM fails to load
• Deduplicate CodeMirror theme and highlight style definitions using factory functions
• Fix CompilerModal dark mode (hardcoded #ffffff background -> var(--vp-c-bg))
• Replace hardcoded button colors with existing CSS variables (--vp-button-brand-*)
• Remove redundant ternary expression
• Bump dependencies