fix(tui): remove duplicate context statusline item (#18054)

Addresses #18045

Problem: `/statusline` exposed both `context-remaining` and
`context-remaining-percent` after conflicting PRs attempted to address
the same context-status issue, including #17637, allowing duplicate
footer segments.

Solution: Remove the duplicate `context-remaining-percent` status-line
item and update status-line tests and snapshots to use only canonical
`context-remaining`.

codex-rs/tui/src/chatwidget/status_surfaces.rs

@@ -450,7 +450,7 @@ impl ChatWidget {
                     Some(format!("{} used", format_tokens_compact(total)))
                 }
             }
-            StatusLineItem::ContextRemaining | StatusLineItem::ContextRemainingPercent => self
+            StatusLineItem::ContextRemaining => self
                 .status_line_context_remaining_percent()
                 .map(|remaining| format!("Context {remaining}% left")),
             StatusLineItem::ContextUsed => self

codex-rs/tui/src/chatwidget/tests/status_and_layout.rs

@@ -914,24 +914,6 @@ async fn status_line_legacy_context_usage_renders_context_used_percent() {
     );
 }
 
-#[tokio::test]
-async fn status_line_context_remaining_percent_renders_labeled_percent() {
-    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(/*model_override*/ None).await;
-    chat.thread_id = Some(ThreadId::new());
-    chat.config.tui_status_line = Some(vec!["context-remaining-percent".to_string()]);
-
-    chat.refresh_status_line();
-
-    assert_eq!(
-        status_line_text(&chat),
-        Some("Context 100% left".to_string())
-    );
-    assert!(
-        drain_insert_history(&mut rx).is_empty(),
-        "context-remaining-percent should remain a valid status line item"
-    );
-}
-
 #[tokio::test]
 async fn status_line_branch_state_resets_when_git_branch_disabled() {
     let (mut chat, _rx, _op_rx) = make_chatwidget_manual(/*model_override*/ None).await;
@@ -1200,7 +1182,7 @@ async fn status_line_model_with_reasoning_fast_footer_snapshot() {
 }
 
 #[tokio::test]
-async fn status_line_model_with_reasoning_context_remaining_percent_footer_snapshot() {
+async fn status_line_model_with_reasoning_context_remaining_footer_snapshot() {
     use ratatui::Terminal;
     use ratatui::backend::TestBackend;
 
@@ -1211,7 +1193,7 @@ async fn status_line_model_with_reasoning_context_remaining_percent_footer_snaps
     chat.config.cwd = test_project_path().abs();
     chat.config.tui_status_line = Some(vec![
         "model-with-reasoning".to_string(),
-        "context-remaining-percent".to_string(),
+        "context-remaining".to_string(),
         "current-dir".to_string(),
     ]);
     chat.set_reasoning_effort(Some(ReasoningEffortConfig::XHigh));
@@ -1228,7 +1210,7 @@ async fn status_line_model_with_reasoning_context_remaining_percent_footer_snaps
         .draw(|f| chat.render(f.area(), f.buffer_mut()))
         .expect("draw model-with-reasoning footer");
     assert_chatwidget_snapshot!(
-        "status_line_model_with_reasoning_context_remaining_percent_footer",
+        "status_line_model_with_reasoning_context_remaining_footer",
         normalized_backend_snapshot(terminal.backend())
     );
 }