[Raing5Days]

Summary of Changes

• Viewport intersection lazy loading: Added \lazy\ prop support to \MonacoEditorCore\ and enabled it by default in \ReadOnlyCodeBlock.
• Eliminate offscreen editor instantiation: When code blocks are rendered outside the readable viewport (e.g. in conversation history, collapsed tools, or documentation previews), creation of the heavy Monaco editor instance (\monaco.editor.create), DOM nodes, and event listeners is deferred until the block intersects within 200px of the viewport.
• Graceful SSR/environment fallback: Automatically falls back to immediate instantiation when \IntersectionObserver\ is unavailable.

Verification

• Unit tests:
  • Added \ReadOnlyCodeBlock.test.tsx\ covering deferred instantiation under \lazy={true}\ until intersection and immediate instantiation when \lazy={false}.
  • \CodeEditor.test.tsx: 15/15 tests passed.
  • Regression verified with full editor test suite.