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/cli/src/main.rs

@@ -38,7 +38,7 @@ use codex_tui::UpdateAction;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_cli::CliConfigOverrides;
 use codex_utils_cli::ProfileV2Name;
-use codex_utils_cli::resume_command;
+use codex_utils_cli::resume_hint;
 use owo_colors::OwoColorize;
 use std::io::IsTerminal;
 use std::path::PathBuf;
@@ -629,6 +629,7 @@ fn format_exit_messages(exit_info: AppExitInfo, color_enabled: bool) -> Vec<Stri
     let AppExitInfo {
         token_usage,
         thread_id: conversation_id,
+        thread_name,
         ..
     } = exit_info;
 
@@ -637,7 +638,7 @@ fn format_exit_messages(exit_info: AppExitInfo, color_enabled: bool) -> Vec<Stri
         lines.push(token_usage.to_string());
     }
 
-    if let Some(resume_cmd) = resume_command(/*thread_name*/ None, conversation_id) {
+    if let Some(resume_cmd) = resume_hint(thread_name.as_deref(), conversation_id) {
         let command = if color_enabled {
             resume_cmd.cyan().to_string()
         } else {
@@ -2689,7 +2690,7 @@ mod tests {
     }
 
     #[test]
-    fn format_exit_messages_uses_id_even_when_thread_has_name() {
+    fn format_exit_messages_names_picker_item_when_thread_has_name() {
         let exit_info = sample_exit_info(
             Some("123e4567-e89b-12d3-a456-426614174000"),
             Some("my-thread"),
@@ -2699,8 +2700,7 @@ mod tests {
             lines,
             vec![
                 "Token usage: total=2 input=0 output=2".to_string(),
-                "To continue this session, run codex resume 123e4567-e89b-12d3-a456-426614174000"
-                    .to_string(),
+                "To continue this session, run codex resume, then select my-thread (123e4567-e89b-12d3-a456-426614174000)".to_string(),
             ]
         );
     }