Clarify resume hints for renamed threads (#23234)

Addresses #23181

## Why
Renamed threads can share names, so hints that suggest resuming directly
by name are ambiguous. Issue #23181 asks for the picker hint to include
the thread name and thread ID in parens so users can disambiguate
safely.

## What
- Adds a shared resume hint formatter for named threads: run `codex
resume`, then select `<name> (<thread-id>)`.
- Uses that hint for /rename confirmations, TUI session summaries, and
CLI/TUI exit messages.
- Keeps direct `codex resume <thread-id>` guidance for unnamed threads.

## Verification
Manually verified that message after `/rename` and after `/exit` include
session ID in parens.

---------

Co-authored-by: Felipe Coury <felipe.coury@openai.com>

codex-rs/tui/src/app/event_dispatch.rs

@@ -152,7 +152,7 @@ impl App {
                                         if let Some(usage_line) = summary.usage_line {
                                             lines.push(usage_line.into());
                                         }
-                                        if let Some(command) = summary.resume_command {
+                                        if let Some(command) = summary.resume_hint {
                                             let spans = vec![
                                                 "To continue this session, run ".into(),
                                                 command.cyan(),

codex-rs/tui/src/app/session_lifecycle.rs

@@ -473,7 +473,7 @@ impl App {
                     if let Some(usage_line) = summary.usage_line {
                         lines.push(usage_line.into());
                     }
-                    if let Some(command) = summary.resume_command {
+                    if let Some(command) = summary.resume_hint {
                         let spans = vec!["To continue this session, run ".into(), command.cyan()];
                         lines.push(spans.into());
                     }
@@ -701,7 +701,7 @@ impl App {
                             if let Some(usage_line) = summary.usage_line {
                                 lines.push(usage_line.into());
                             }
-                            if let Some(command) = summary.resume_command {
+                            if let Some(command) = summary.resume_hint {
                                 let spans =
                                     vec!["To continue this session, run ".into(), command.cyan()];
                                 lines.push(spans.into());

codex-rs/tui/src/app/tests/session_summary.rs

@@ -57,13 +57,13 @@ async fn session_summary_includes_resume_hint_for_persisted_rollout() {
         Some("Token usage: total=12 input=10 output=2".to_string())
     );
     assert_eq!(
-        summary.resume_command,
+        summary.resume_hint,
         Some("codex resume 123e4567-e89b-12d3-a456-426614174000".to_string())
     );
 }
 
 #[tokio::test]
-async fn session_summary_uses_id_even_when_thread_has_name() {
+async fn session_summary_names_picker_item_when_thread_has_name() {
     let usage = TokenUsage {
         input_tokens: 10,
         output_tokens: 2,
@@ -83,7 +83,10 @@ async fn session_summary_uses_id_even_when_thread_has_name() {
     )
     .expect("summary");
     assert_eq!(
-        summary.resume_command,
-        Some("codex resume 123e4567-e89b-12d3-a456-426614174000".to_string())
+        summary.resume_hint,
+        Some(
+            "codex resume, then select my-session (123e4567-e89b-12d3-a456-426614174000)"
+                .to_string()
+        )
     );
 }