migrate from tui-textarea to ratatui-textarea

Replace tui-textarea 0.7 with ratatui-textarea 0.8, the ratatui-org
maintained fork. Also upgrade ratatui 0.29->0.30 and crossterm 0.28->0.29
which are required by ratatui-textarea 0.8.

The API is identical so only import paths changed.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: pm100