refactor: remove AttachImage tui event (#3191)

TuiEvent is supposed to be purely events that come from the "driver",
i.e. events from the terminal. Everything app-specific should be an
AppEvent. In this case, it didn't need to be an event at all.

codex-rs/tui/src/chatwidget.rs

@@ -57,6 +57,7 @@ use crate::bottom_pane::CancellationEvent;
 use crate::bottom_pane::InputResult;
 use crate::bottom_pane::SelectionAction;
 use crate::bottom_pane::SelectionItem;
+use crate::clipboard_paste::paste_image_to_temp_png;
 use crate::get_git_diff::get_git_diff;
 use crate::history_cell;
 use crate::history_cell::CommandOutput;
@@ -745,6 +746,17 @@ impl ChatWidget {
                 self.on_ctrl_c();
                 return;
             }
+            KeyEvent {
+                code: KeyCode::Char('v'),
+                modifiers: KeyModifiers::CONTROL,
+                kind: KeyEventKind::Press,
+                ..
+            } => {
+                if let Ok((path, info)) = paste_image_to_temp_png() {
+                    self.attach_image(path, info.width, info.height, info.encoded_format.label());
+                }
+                return;
+            }
             other if other.kind == KeyEventKind::Press => {
                 self.bottom_pane.clear_ctrl_c_quit_hint();
             }