[connectors] Support connectors part 2 - slash command and tui (#9728)

- [x] Support `/apps` slash command to browse the apps in tui.
- [x] Support inserting apps to prompt using `$`.
- [x] Lots of simplification/renaming from connectors to apps.

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

@@ -0,0 +1,163 @@
+use crossterm::event::KeyCode;
+use crossterm::event::KeyEvent;
+use ratatui::buffer::Buffer;
+use ratatui::layout::Constraint;
+use ratatui::layout::Layout;
+use ratatui::layout::Rect;
+use ratatui::style::Stylize;
+use ratatui::text::Line;
+use ratatui::widgets::Block;
+use ratatui::widgets::Paragraph;
+use ratatui::widgets::Widget;
+use textwrap::wrap;
+
+use super::CancellationEvent;
+use super::bottom_pane_view::BottomPaneView;
+use crate::key_hint;
+use crate::render::Insets;
+use crate::render::RectExt as _;
+use crate::style::user_message_style;
+use crate::wrapping::word_wrap_lines;
+
+pub(crate) struct AppLinkView {
+    title: String,
+    description: Option<String>,
+    instructions: String,
+    url: String,
+    is_installed: bool,
+    complete: bool,
+}
+
+impl AppLinkView {
+    pub(crate) fn new(
+        title: String,
+        description: Option<String>,
+        instructions: String,
+        url: String,
+        is_installed: bool,
+    ) -> Self {
+        Self {
+            title,
+            description,
+            instructions,
+            url,
+            is_installed,
+            complete: false,
+        }
+    }
+
+    fn content_lines(&self, width: u16) -> Vec<Line<'static>> {
+        let usable_width = width.max(1) as usize;
+        let mut lines: Vec<Line<'static>> = Vec::new();
+
+        lines.push(Line::from(self.title.clone().bold()));
+        if let Some(description) = self
+            .description
+            .as_deref()
+            .map(str::trim)
+            .filter(|description| !description.is_empty())
+        {
+            for line in wrap(description, usable_width) {
+                lines.push(Line::from(line.into_owned().dim()));
+            }
+        }
+        lines.push(Line::from(""));
+        if self.is_installed {
+            for line in wrap("Use $ to insert this app into the prompt.", usable_width) {
+                lines.push(Line::from(line.into_owned()));
+            }
+            lines.push(Line::from(""));
+        }
+
+        let instructions = self.instructions.trim();
+        if !instructions.is_empty() {
+            for line in wrap(instructions, usable_width) {
+                lines.push(Line::from(line.into_owned()));
+            }
+            for line in wrap(
+                "Newly installed apps can take a few minutes to appear in /apps.",
+                usable_width,
+            ) {
+                lines.push(Line::from(line.into_owned()));
+            }
+            if !self.is_installed {
+                for line in wrap(
+                    "After installed, use $ to insert this app into the prompt.",
+                    usable_width,
+                ) {
+                    lines.push(Line::from(line.into_owned()));
+                }
+            }
+            lines.push(Line::from(""));
+        }
+
+        lines.push(Line::from(vec!["Open:".dim()]));
+        let url_line = Line::from(vec![self.url.clone().cyan().underlined()]);
+        lines.extend(word_wrap_lines(vec![url_line], usable_width));
+
+        lines
+    }
+}
+
+impl BottomPaneView for AppLinkView {
+    fn handle_key_event(&mut self, key_event: KeyEvent) {
+        if let KeyEvent {
+            code: KeyCode::Esc, ..
+        } = key_event
+        {
+            self.on_ctrl_c();
+        }
+    }
+
+    fn on_ctrl_c(&mut self) -> CancellationEvent {
+        self.complete = true;
+        CancellationEvent::Handled
+    }
+
+    fn is_complete(&self) -> bool {
+        self.complete
+    }
+}
+
+impl crate::render::renderable::Renderable for AppLinkView {
+    fn desired_height(&self, width: u16) -> u16 {
+        let content_width = width.saturating_sub(4).max(1);
+        let content_lines = self.content_lines(content_width);
+        content_lines.len() as u16 + 3
+    }
+
+    fn render(&self, area: Rect, buf: &mut Buffer) {
+        if area.height == 0 || area.width == 0 {
+            return;
+        }
+
+        Block::default()
+            .style(user_message_style())
+            .render(area, buf);
+
+        let [content_area, hint_area] =
+            Layout::vertical([Constraint::Fill(1), Constraint::Length(1)]).areas(area);
+        let inner = content_area.inset(Insets::vh(1, 2));
+        let content_width = inner.width.max(1);
+        let lines = self.content_lines(content_width);
+        Paragraph::new(lines).render(inner, buf);
+
+        if hint_area.height > 0 {
+            let hint_area = Rect {
+                x: hint_area.x.saturating_add(2),
+                y: hint_area.y,
+                width: hint_area.width.saturating_sub(2),
+                height: hint_area.height,
+            };
+            hint_line().dim().render(hint_area, buf);
+        }
+    }
+}
+
+fn hint_line() -> Line<'static> {
+    Line::from(vec![
+        "Press ".into(),
+        key_hint::plain(KeyCode::Esc).into(),
+        " to close".into(),
+    ])
+}