Feat/textarea row measurement min max (#14)

* feat(textarea): add row measurement API with configurable min/max bounds

- add TextAreaMeasure and TextArea::measure(width_cols)
- make measurement wrap-aware and include block chrome rows
- add set_min_rows/set_max_rows (+ getters) with invariant normalization
- clamp preferred_rows to effective [min_rows, max_rows]
- export TextAreaMeasure at crate root
- switch examples/variable.rs to measured preferred_rows
- add integration tests for measure + min/max behavior

* chore(release): bump to v0.10.0 and update changelog

Cargo.toml

@@ -3,7 +3,7 @@ name = "tui-textarea-2"
 homepage = "https://github.com/srothgan/tui-textarea#readme"
 repository = "https://github.com/srothgan/tui-textarea"
 documentation = "https://docs.rs/tui-textarea-2/latest/tui_textarea/"
-version = "0.9.2"
+version = "0.10.0"
 edition = "2024"
 rust-version = "1.85.0" # for Rust 2024 edition support
 authors = ["Simon Peter Rothgang <simonrothgang@icloud.com>", "rhysd <lin90162@yahoo.co.jp>"]