Show Daybreak notices after the session header (#54097)

## What changed

Emit the Daybreak notice after replacing or removing the placeholder session header so the notice follows the configured header.

## Testing

Extend the resumed-history snapshot test to start with a placeholder header and verify the full transcript order: session header, Daybreak notice, and replayed user and assistant messages.

GitOrigin-RevId: 536f717b2859d2fe319756f52123b4cd0407cb66

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

@@ -118,9 +118,6 @@ impl ChatWidget {
         self.config.cwd = session.cwd.clone();
         self.config.model_provider_id = session.model_provider_id.clone();
         self.set_daybreak_enabled(self.daybreak_enabled);
-        if self.daybreak_enabled && previous_thread_id != self.thread_id {
-            self.add_info_message("Daybreak is on for new turns.".into(), /*hint*/ None);
-        }
         if connector_scope_changed {
             self.invalidate_connector_scope();
         }
@@ -235,6 +232,10 @@ impl ChatWidget {
             self.transcript.active_cell = None;
             self.bump_active_cell_revision();
         }
+        // Emit notices after replacing or removing the placeholder header.
+        if self.daybreak_enabled && previous_thread_id != self.thread_id {
+            self.add_info_message("Daybreak is on for new turns.".into(), /*hint*/ None);
+        }
         self.transcript.saw_copy_source_this_turn = false;
         self.refresh_skills_for_current_cwd(/*force_reload*/ true);
         self.refresh_connector_mentions(/*force_refresh*/ false);

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

@@ -70,7 +70,12 @@ async fn resumed_initial_messages_render_history() {
     );
 
     // Session hydration can precede the account update on ChatGPT sign-in.
-    chat.status_account_display = None;
+    let (mut chat, mut rx, _ops) = make_chatwidget_manual(/*model_override*/ None).await;
+    chat.set_feature_enabled(Feature::CliDaybreak, /*enabled*/ true);
+    chat.show_welcome_banner = false;
+    chat.local_settings.tui.show_tooltips = false;
+    chat.config.cwd = configured.cwd.clone();
+    chat.transcript.active_cell = Some(ChatWidget::placeholder_session_header_cell(&chat.config));
     configured.thread_id = ThreadId::new();
     chat.handle_thread_session(configured);
     assert!(chat.daybreak_enabled);
@@ -92,27 +97,18 @@ async fn resumed_initial_messages_render_history() {
         ReplayKind::ResumeInitialMessages,
     );
 
-    let cells = drain_insert_history(&mut rx);
-    let mut merged_lines = Vec::new();
-    for lines in cells {
-        let text = lines
-            .iter()
-            .flat_map(|line| line.spans.iter())
-            .map(|span| span.content.clone())
-            .collect::<String>();
-        merged_lines.push(text);
-    }
-
-    let text_blob = merged_lines.join("\n");
-    assert!(
-        text_blob.contains("hello from user"),
-        "expected replayed user message",
-    );
-    assert!(
-        text_blob.contains("assistant reply"),
-        "expected replayed agent message",
-    );
-    insta::assert_snapshot!("resumed_daybreak_banner", merged_lines[0]);
+    let history = drain_insert_history(&mut rx)
+        .iter()
+        .flatten()
+        .map(ToString::to_string)
+        .collect::<Vec<_>>()
+        .join("\n")
+        .replace(CODEX_CLI_VERSION, "<VERSION>")
+        .replace(
+            &test_path_display("/home/user/project"),
+            "/home/user/project",
+        );
+    insta::assert_snapshot!("resumed_daybreak_banner", history);
 }
 
 #[tokio::test]

codex-rs/tui/src/chatwidget/tests/snapshots/codex_tui__chatwidget__tests__history_replay__resumed_daybreak_banner.snap

@@ -1,5 +1,16 @@
 ---
 source: tui/src/chatwidget/tests/history_replay.rs
-expression: "merged_lines[0]"
+assertion_line: 111
+expression: history
 ---
+
+  >_ OpenAI Codex (v<VERSION>)
+     /home/user/project
+
 • Daybreak is on for new turns.
+
+
+› hello from user
+
+
+• assistant reply