rework patch/exec approval UI (#4573)

| Scenario | Screenshot |
| ---------------------- |
----------------------------------------------------------------------------------------------------------------------------------------------------
|
| short patch | <img width="1096" height="533" alt="short patch"
src="https://github.com/user-attachments/assets/8a883429-0965-4c0b-9002-217b3759b557"
/> |
| short command | <img width="1096" height="533" alt="short command"
src="https://github.com/user-attachments/assets/901abde8-2494-4e86-b98a-7cabaf87ca9c"
/> |
| long patch | <img width="1129" height="892" alt="long patch"
src="https://github.com/user-attachments/assets/fa799a29-a0d6-48e6-b2ef-10302a7916d3"
/> |
| long command | <img width="1096" height="892" alt="long command"
src="https://github.com/user-attachments/assets/11ddf79b-98cb-4b60-ac22-49dfa7779343"
/> |
| viewing complete patch | <img width="1129" height="892" alt="viewing
complete patch"
src="https://github.com/user-attachments/assets/81666958-af94-420e-aa66-b60d0a42b9db"
/> |

codex-rs/tui/src/render/renderable.rs

@@ -0,0 +1,102 @@
+use ratatui::buffer::Buffer;
+use ratatui::layout::Rect;
+use ratatui::text::Line;
+use ratatui::widgets::Paragraph;
+use ratatui::widgets::WidgetRef;
+
+pub trait Renderable {
+    fn render(&self, area: Rect, buf: &mut Buffer);
+    fn desired_height(&self, width: u16) -> u16;
+}
+
+impl Renderable for () {
+    fn render(&self, _area: Rect, _buf: &mut Buffer) {}
+    fn desired_height(&self, _width: u16) -> u16 {
+        0
+    }
+}
+
+impl Renderable for &str {
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        self.render_ref(area, buf);
+    }
+    fn desired_height(&self, _width: u16) -> u16 {
+        1
+    }
+}
+
+impl Renderable for String {
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        self.render_ref(area, buf);
+    }
+    fn desired_height(&self, _width: u16) -> u16 {
+        1
+    }
+}
+
+impl<'a> Renderable for Line<'a> {
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        WidgetRef::render_ref(self, area, buf);
+    }
+    fn desired_height(&self, _width: u16) -> u16 {
+        1
+    }
+}
+
+impl<'a> Renderable for Paragraph<'a> {
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        self.render_ref(area, buf);
+    }
+    fn desired_height(&self, width: u16) -> u16 {
+        self.line_count(width) as u16
+    }
+}
+
+impl<R: Renderable> Renderable for Option<R> {
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        if let Some(renderable) = self {
+            renderable.render(area, buf);
+        }
+    }
+
+    fn desired_height(&self, width: u16) -> u16 {
+        if let Some(renderable) = self {
+            renderable.desired_height(width)
+        } else {
+            0
+        }
+    }
+}
+
+pub struct ColumnRenderable {
+    children: Vec<Box<dyn Renderable>>,
+}
+
+impl Renderable for ColumnRenderable {
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        let mut y = area.y;
+        for child in &self.children {
+            let child_area = Rect::new(area.x, y, area.width, child.desired_height(area.width))
+                .intersection(area);
+            if !child_area.is_empty() {
+                child.render(child_area, buf);
+            }
+            y += child_area.height;
+        }
+    }
+
+    fn desired_height(&self, width: u16) -> u16 {
+        self.children
+            .iter()
+            .map(|child| child.desired_height(width))
+            .sum()
+    }
+}
+
+impl ColumnRenderable {
+    pub fn new(children: impl IntoIterator<Item = Box<dyn Renderable>>) -> Self {
+        Self {
+            children: children.into_iter().collect(),
+        }
+    }
+}