Add comprehensive JSDoc explaining the implicit-context pattern for
onNodeMounted and onNodeRemoved hooks:
- Document how the runtime sets a global scope slot before nodeCreated()
- Explain why hooks must be called synchronously (Vue-style constraint)
- Add code examples showing correct vs incorrect async usage
- Document automatic cleanup and memory-safety benefits
Per design review decision #7.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>