feat(textarea): add native cursor render mode (#26)

* feat(textarea): add native cursor render mode

- Add CursorRenderMode::{Cell, Hidden} and TextArea accessors for render mode plus rendered_cursor_position().
- Store the terminal-relative cursor position from a shared render plan that accounts for blocks, line numbers, scroll, wrapping, tabs, and wide Unicode.
- Let hidden mode suppress only the textarea-owned cursor cell while preserving default Cell rendering and set_cursor_style behavior.
- Document native cursor integration and add focused tests for default rendering, hidden rendering, placeholders, and cursor-position edge cases.

* chore: prepare 0.12.1 release

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## [0.12.1] - 2026-07-10 [Changes][v0.12.1]
+
+### Features
+
+- **Native cursor integration** (#26, @srothgan): Add opt-in `CursorRenderMode::Hidden` and `TextArea::rendered_cursor_position()` for placing backend-owned terminal cursors while preserving the default buffer-drawn cursor behavior.
+
 ## [0.12.0] - 2026-06-30 [Changes][v0.12.0]
 
 ### Features
@@ -491,6 +497,7 @@ First release :tada:
 - docs.rs: https://docs.rs/tui-textarea/latest/tui_textarea/
 
 
+[v0.12.1]: https://github.com/srothgan/tui-textarea/compare/v0.12.0...v0.12.1
 [v0.12.0]: https://github.com/srothgan/tui-textarea/compare/v0.11.0...v0.12.0
 [v0.11.0]: https://github.com/srothgan/tui-textarea/compare/v0.10.2...v0.11.0
 [v0.10.2]: https://github.com/srothgan/tui-textarea/compare/v0.10.1...v0.10.2