- Refactored chunk rendering to compute prologue and body line counts separately via new `chunk_head_body_lines()` function.
- Updated ellipsis marker format from line count to line range selection syntax (e.g., 'to expand above/below').
- Modified `render()` method signature to accept `head_lines` and `body_lines` parameters for precise line count display.
- Simplified no-changes response in chunk edit mode to omit redundant text when content matches.
- Expanded chunk-edit documentation with compound statement examples and region suffix behavior for non-code formats.