fix(codex-rs): clean dev-fast build warnings

- Remove unnecessary mut on Browser values; keep handler mutable
- Drop unused locals in chatwidget; underscore elapsed in history_cell
- Silence dead_code for ShowChromeOptions variant

Verified via ./build-fast.sh showing zero warnings.

codex-rs/browser/src/manager.rs

@@ -224,7 +224,7 @@ impl BrowserManager {
                 let ws_clone = ws.clone();
                 let handle = tokio::spawn(async move { Browser::connect(ws_clone).await });
                 match tokio::time::timeout(attempt_timeout, handle).await {
-                    Ok(Ok(Ok((mut browser, mut handler)))) => {
+                    Ok(Ok(Ok((browser, mut handler)))) => {
                         info!("[cdp/bm] WS connect attempt {} succeeded", attempt);
 
                         // Start event handler loop
@@ -338,7 +338,7 @@ impl BrowserManager {
                     let handle = tokio::spawn(async move { Browser::connect(ws_clone).await });
 
                     match tokio::time::timeout(attempt_timeout, handle).await {
-                        Ok(Ok(Ok((mut browser, mut handler)))) => {
+                        Ok(Ok(Ok((browser, mut handler)))) => {
                             info!("[cdp/bm] WS connect attempt {} succeeded", attempt);
                             info!("[cdp/bm] Connected to Chrome in {:?}", connect_start.elapsed());
 
@@ -435,7 +435,7 @@ impl BrowserManager {
                 let ws_clone = ws.clone();
                 let handle = tokio::spawn(async move { Browser::connect(ws_clone).await });
             match tokio::time::timeout(attempt_timeout, handle).await {
-                Ok(Ok(Ok((mut browser, mut handler)))) => {
+                Ok(Ok(Ok((browser, mut handler)))) => {
                     info!("[cdp/bm] WS connect attempt {} succeeded", attempt);
                     // Start event handler loop
                     let task = tokio::spawn(async move { while let Some(_evt) = handler.next().await {} });
@@ -546,7 +546,7 @@ impl BrowserManager {
                     let ws_clone = ws.clone();
                     let handle = tokio::spawn(async move { Browser::connect(ws_clone).await });
                     match tokio::time::timeout(attempt_timeout, handle).await {
-                        Ok(Ok(Ok((mut browser, mut handler)))) => {
+                        Ok(Ok(Ok((browser, mut handler)))) => {
                             info!("[cdp/bm] WS connect attempt {} succeeded", attempt);
                             info!(
                                 "Step 4: Connected to Chrome in {:?}",

codex-rs/tui/src/app_event.rs

@@ -92,6 +92,7 @@ pub(crate) enum AppEvent {
     OnboardingComplete(ChatWidgetArgs),
 
     /// Show Chrome launch options dialog
+    #[allow(dead_code)]
     ShowChromeOptions(Option<u16>),
 
     /// Chrome launch option selected by user

codex-rs/tui/src/chatwidget.rs

@@ -3481,7 +3481,6 @@ impl ChatWidget<'_> {
         let latest_screenshot = self.latest_browser_screenshot.clone();
         let app_event_tx = self.app_event_tx.clone();
         let port_display = port.map_or("auto-detect".to_string(), |p| p.to_string());
-        let launch_port = port.unwrap_or(9222);
 
         // Add status message to chat
         let status_msg = format!(
@@ -4304,10 +4303,7 @@ impl WidgetRef for &ChatWidget<'_> {
         let mut welcome_overlay: Option<&dyn HistoryCell> = None;
 
         // Add all history cells
-        for (idx, cell) in self.history_cells.iter().enumerate() {
-            let is_animating = cell.is_animating();
-            let has_custom = cell.has_custom_render();
-            let height = cell.desired_height(content_area.width);
+        for cell in self.history_cells.iter() {
             
             // suppress noisy per-cell animation logs
             // If this is the animated welcome cell, render it as an overlay instead

codex-rs/tui/src/history_cell.rs

@@ -375,7 +375,7 @@ impl HistoryCell for AnimatedWelcomeCell {
     }
     
     fn custom_render(&self, area: Rect, buf: &mut Buffer) {
-        let elapsed = self.start_time.elapsed();
+        let _elapsed = self.start_time.elapsed();
         
         // Center the animation within the provided area
         // The actual animation needs 21 rows