feat: unified exec footer (#8117)

# With `unified_exec`
Known tools are correctly casted
<img width="1150" height="312" alt="Screenshot 2025-12-16 at 19 27 28"
src="https://github.com/user-attachments/assets/24150ee5-e88d-461b-a459-483c24784196"
/>
If a session exit the turn, we render it with the "Ran ..."
<img width="1168" height="355" alt="Screenshot 2025-12-16 at 19 27 58"
src="https://github.com/user-attachments/assets/3f00b60c-2d57-4f9d-a201-9cc8388957cb"
/>
If a session does not exit during the turn, it is closed at the end of
the turn but this is not rendered
<img width="642" height="342" alt="Screenshot 2025-12-16 at 19 34 37"
src="https://github.com/user-attachments/assets/c2bd9283-7017-4915-ba73-c52199b0b28e"
/>

# Without `unified_exec`
No changes
<img width="740" height="603" alt="Screenshot 2025-12-16 at 19 31 21"
src="https://github.com/user-attachments/assets/ca5d90fe-a9b2-42ba-bcd7-3e98c4ed22e8"
/>

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

@@ -389,6 +389,7 @@ fn make_chatwidget_manual(
         suppressed_exec_calls: HashSet::new(),
         last_unified_wait: None,
         task_complete_pending: false,
+        unified_exec_sessions: Vec::new(),
         mcp_startup_status: None,
         interrupts: InterruptManager::new(),
         reasoning_buffer: String::new(),
@@ -1184,6 +1185,7 @@ fn exec_end_without_begin_uses_event_command() {
 #[test]
 fn exec_history_shows_unified_exec_startup_commands() {
     let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(None);
+    chat.on_task_started();
 
     let begin = begin_exec_with_source(
         &mut chat,
@@ -1207,6 +1209,46 @@ fn exec_history_shows_unified_exec_startup_commands() {
     );
 }
 
+#[test]
+fn exec_history_shows_unified_exec_tool_calls() {
+    let (mut chat, _rx, _op_rx) = make_chatwidget_manual(None);
+    chat.on_task_started();
+
+    let begin = begin_exec_with_source(
+        &mut chat,
+        "call-startup",
+        "ls",
+        ExecCommandSource::UnifiedExecStartup,
+    );
+    end_exec(&mut chat, begin, "", "", 0);
+
+    let blob = active_blob(&chat);
+    assert_eq!(blob, "• Explored\n  └ List ls\n");
+}
+
+#[test]
+fn unified_exec_end_after_task_complete_is_suppressed() {
+    let (mut chat, mut rx, _op_rx) = make_chatwidget_manual(None);
+    chat.on_task_started();
+
+    let begin = begin_exec_with_source(
+        &mut chat,
+        "call-startup",
+        "echo unified exec startup",
+        ExecCommandSource::UnifiedExecStartup,
+    );
+    drain_insert_history(&mut rx);
+
+    chat.on_task_complete(None);
+    end_exec(&mut chat, begin, "", "", 0);
+
+    let cells = drain_insert_history(&mut rx);
+    assert!(
+        cells.is_empty(),
+        "expected unified exec end after task complete to be suppressed"
+    );
+}
+
 /// Selecting the custom prompt option from the review popup sends
 /// OpenReviewCustomPrompt to the app event channel.
 #[test]