chore: auto format code on save and add more details to AGENTS.md (#1582)

Adds a default vscode config with generally applicable settings.
Adds more entrypoints to justfile both  for environment setup and to help
agents better verify changes.

codex-rs/tui/src/app.rs

@@ -60,7 +60,7 @@ struct ChatWidgetArgs {
     initial_images: Vec<PathBuf>,
 }
 
-impl<'a> App<'a> {
+impl App<'_> {
     pub(crate) fn new(
         config: Config,
         initial_prompt: Option<String>,

codex-rs/tui/src/bottom_pane/status_indicator_view.rs

@@ -24,7 +24,7 @@ impl StatusIndicatorView {
     }
 }
 
-impl<'a> BottomPaneView<'a> for StatusIndicatorView {
+impl BottomPaneView<'_> for StatusIndicatorView {
     fn update_status_text(&mut self, text: String) -> ConditionalUpdate {
         self.update_text(text);
         ConditionalUpdate::NeedsRedraw