Login flow polish (#3632)

# Description
- Update sign in flow

# Tests
- Passes CI

---------

Co-authored-by: Michael Bolin <mbolin@openai.com>

codex-rs/tui/src/onboarding/auth.rs

@@ -137,12 +137,12 @@ impl AuthModeWidget {
     fn render_pick_mode(&self, area: Rect, buf: &mut Buffer) {
         let mut lines: Vec<Line> = vec![
             Line::from(vec![
-                "> ".into(),
-                "Sign in with ChatGPT to use Codex as part of your paid plan".bold(),
+                "  ".into(),
+                "Sign in with ChatGPT to use Codex as part of your paid plan".into(),
             ]),
             Line::from(vec![
                 "  ".into(),
-                "or connect an API key for usage-based billing".bold(),
+                "or connect an API key for usage-based billing".into(),
             ]),
             "".into(),
         ];
@@ -182,6 +182,7 @@ impl AuthModeWidget {
             "Sign in with ChatGPT",
             "Usage included with Plus, Pro, and Team plans",
         ));
+        lines.push("".into());
         lines.extend(create_mode_item(
             1,
             AuthMode::ApiKey,
@@ -205,7 +206,7 @@ impl AuthModeWidget {
     }
 
     fn render_continue_in_browser(&self, area: Rect, buf: &mut Buffer) {
-        let mut spans = vec!["> ".into()];
+        let mut spans = vec!["  ".into()];
         // Schedule a follow-up frame to keep the shimmer animation going.
         self.request_frame
             .schedule_frame_in(std::time::Duration::from_millis(100));
@@ -217,7 +218,8 @@ impl AuthModeWidget {
             && !state.auth_url.is_empty()
         {
             lines.push("  If the link doesn't open automatically, open the following link to authenticate:".into());
-            lines.push(vec!["  ".into(), state.auth_url.as_str().cyan().underlined()].into());
+            lines.push("".into());
+            lines.push(Line::from(state.auth_url.as_str().cyan().underlined()));
             lines.push("".into());
         }
 
@@ -231,7 +233,7 @@ impl AuthModeWidget {
         let lines = vec![
             "✓ Signed in with your ChatGPT account".fg(Color::Green).into(),
             "".into(),
-            "> Before you start:".into(),
+            "  Before you start:".into(),
             "".into(),
             "  Decide how much autonomy you want to grant Codex".into(),
             Line::from(vec![

codex-rs/tui/src/onboarding/onboarding_screen.rs

@@ -24,6 +24,7 @@ use crate::tui::TuiEvent;
 use color_eyre::eyre::Result;
 use std::sync::Arc;
 use std::sync::RwLock;
+use std::time::Instant;
 
 #[allow(clippy::large_enum_variant)]
 enum Step {
@@ -74,6 +75,8 @@ impl OnboardingScreen {
         let codex_home = config.codex_home;
         let mut steps: Vec<Step> = vec![Step::Welcome(WelcomeWidget {
             is_logged_in: !matches!(login_status, LoginStatus::NotAuthenticated),
+            request_frame: tui.frame_requester(),
+            start: Instant::now(),
         })];
         if show_login_screen {
             steps.push(Step::Auth(AuthModeWidget {

codex-rs/tui/src/onboarding/welcome.rs

@@ -3,23 +3,62 @@ use ratatui::layout::Rect;
 use ratatui::prelude::Widget;
 use ratatui::style::Stylize;
 use ratatui::text::Line;
+use ratatui::widgets::Paragraph;
 use ratatui::widgets::WidgetRef;
+use ratatui::widgets::Wrap;
 
+use crate::frames::FRAME_TICK_DEFAULT;
+use crate::frames::FRAMES_DEFAULT;
 use crate::onboarding::onboarding_screen::StepStateProvider;
+use crate::tui::FrameRequester;
 
 use super::onboarding_screen::StepState;
+use std::time::Duration;
+use std::time::Instant;
+
+const FRAME_TICK: Duration = FRAME_TICK_DEFAULT;
 
 pub(crate) struct WelcomeWidget {
     pub is_logged_in: bool,
+    pub request_frame: FrameRequester,
+    pub start: Instant,
 }
 
 impl WidgetRef for &WelcomeWidget {
     fn render_ref(&self, area: Rect, buf: &mut Buffer) {
-        let line = Line::from(vec![
-            ">_ ".into(),
-            "Welcome to Codex, OpenAI's command-line coding agent".bold(),
-        ]);
-        line.render(area, buf);
+        let elapsed_ms = self.start.elapsed().as_millis();
+
+        // Align next draw to the next FRAME_TICK boundary to reduce jitter.
+        {
+            let tick_ms = FRAME_TICK.as_millis();
+            let rem_ms = elapsed_ms % tick_ms;
+            let delay_ms = if rem_ms == 0 {
+                tick_ms
+            } else {
+                tick_ms - rem_ms
+            };
+            // Safe cast: delay_ms < tick_ms and FRAME_TICK is small.
+            self.request_frame
+                .schedule_frame_in(Duration::from_millis(delay_ms as u64));
+        }
+
+        let frames = &FRAMES_DEFAULT;
+        let idx = ((elapsed_ms / FRAME_TICK.as_millis()) % frames.len() as u128) as usize;
+
+        let mut lines: Vec<Line> = Vec::with_capacity(frames.len() + 2);
+        lines.extend(frames[idx].lines().map(|l| l.into()));
+
+        lines.push("".into());
+        lines.push(Line::from(vec![
+            "  ".into(),
+            "Welcome to ".into(),
+            "Codex".bold(),
+            ", OpenAI's command-line coding agent".into(),
+        ]));
+
+        Paragraph::new(lines)
+            .wrap(Wrap { trim: false })
+            .render(area, buf);
     }
 }
 
@@ -31,3 +70,14 @@ impl StepStateProvider for WelcomeWidget {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// A number of things break down if FRAME_TICK is zero.
+    #[test]
+    fn frame_tick_must_be_nonzero() {
+        assert!(FRAME_TICK.as_millis() > 0);
+    }
+}