Remove App implementation: delete TUI application logic, event handling, and related structures.

crates/owlen-tui/src/ui.rs

@@ -7,7 +7,8 @@ use textwrap::{wrap, Options};
 use tui_textarea::TextArea;
 use unicode_width::UnicodeWidthStr;
 
-use crate::chat_app::{ChatApp, InputMode};
+use crate::chat_app::ChatApp;
+use owlen_core::ui::{FocusedPanel, InputMode};
 use owlen_core::types::Role;
 
 pub fn render_chat(frame: &mut Frame<'_>, app: &mut ChatApp) {
@@ -436,7 +437,6 @@ fn render_header(frame: &mut Frame<'_>, area: Rect, app: &ChatApp) {
     frame.render_widget(paragraph, inner_area);
 }
 
-use crate::chat_app::FocusedPanel;
 
 fn apply_visual_selection(lines: Vec<Line>, selection: Option<((usize, usize), (usize, usize))>) -> Vec<Line> {
     if let Some(((start_row, start_col), (end_row, end_col))) = selection {