Trim TUI legacy core helper usage (#22695)

## Why

The TUI still had a few low-risk dependencies flowing through the
transitional `legacy_core` namespace after the app-server migration.
These helpers either already have clearer non-core owners or are
presentation logic that does not belong in `codex-core`, so moving them
out reduces the compatibility surface without changing product behavior.

## What changed

This is a low-risk change, almost completely mechanical in nature.

- Route TUI Codex-home lookup through `codex-utils-home-dir`, use
`Config::log_dir` directly, and call
`codex-sandboxing::system_bwrap_warning` without going through
`legacy_core`.
- Move shared `codex resume` hint formatting from `codex-core` into
`codex-utils-cli`.
- Update CLI and TUI call sites to use the shared CLI utility, and keep
the resume-command behavior covered by tests in its new home.

## Verification

- `cargo test -p codex-utils-cli`
- `cargo test -p codex-utils-cli resume_command`

codex-rs/tui/src/app.rs

@@ -397,8 +397,7 @@ fn session_summary(
     let usage_line = (!token_usage.is_zero()).then(|| token_usage.to_string());
     let thread_id =
         resumable_thread(thread_id, thread_name, rollout_path).map(|thread| thread.thread_id);
-    let resume_command =
-        crate::legacy_core::util::resume_command(/*thread_name*/ None, thread_id);
+    let resume_command = codex_utils_cli::resume_command(/*thread_name*/ None, thread_id);
 
     if usage_line.is_none() && resume_command.is_none() {
         return None;

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

@@ -66,9 +66,9 @@ pub(super) fn emit_project_config_warnings(app_event_tx: &AppEventSender, config
 }
 
 pub(super) fn emit_system_bwrap_warning(app_event_tx: &AppEventSender, config: &Config) {
-    let Some(message) = crate::legacy_core::config::system_bwrap_warning(
-        config.permissions.permission_profile.get(),
-    ) else {
+    let Some(message) =
+        codex_sandboxing::system_bwrap_warning(config.permissions.permission_profile.get())
+    else {
         return;
     };
 

codex-rs/tui/src/chatwidget.rs

@@ -165,6 +165,7 @@ use codex_terminal_detection::TerminalInfo;
 use codex_terminal_detection::TerminalName;
 use codex_terminal_detection::terminal_info;
 use codex_utils_absolute_path::AbsolutePathBuf;
+use codex_utils_cli::resume_command;
 use crossterm::event::KeyCode;
 use crossterm::event::KeyEvent;
 use crossterm::event::KeyEventKind;
@@ -1433,8 +1434,8 @@ impl ChatWidget {
     }
 
     fn rename_confirmation_cell(name: &str, thread_id: Option<ThreadId>) -> PlainHistoryCell {
-        let resume_cmd = crate::legacy_core::util::resume_command(Some(name), thread_id)
-            .unwrap_or_else(|| format!("codex resume {name}"));
+        let resume_cmd =
+            resume_command(Some(name), thread_id).unwrap_or_else(|| format!("codex resume {name}"));
         let name = name.to_string();
         let line = vec![
             "• ".into(),

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

@@ -7,7 +7,7 @@ use super::*;
 
 impl ChatWidget {
     pub(super) fn open_theme_picker(&mut self) {
-        let codex_home = crate::legacy_core::config::find_codex_home().ok();
+        let codex_home = codex_utils_home_dir::find_codex_home().ok();
         let terminal_width = self
             .last_rendered_width
             .get()

codex-rs/tui/src/lib.rs

@@ -7,7 +7,6 @@ use crate::legacy_core::check_execpolicy_for_warnings;
 use crate::legacy_core::config::Config;
 use crate::legacy_core::config::ConfigBuilder;
 use crate::legacy_core::config::ConfigOverrides;
-use crate::legacy_core::config::find_codex_home;
 use crate::legacy_core::config::load_config_as_toml_with_cli_and_load_options;
 use crate::legacy_core::config::resolve_oss_provider;
 use crate::legacy_core::config::resolve_profile_v2_config_path;
@@ -56,6 +55,7 @@ use codex_rollout::state_db;
 use codex_state::log_db;
 use codex_utils_absolute_path::AbsolutePathBuf;
 use codex_utils_absolute_path::canonicalize_existing_preserving_symlinks;
+use codex_utils_home_dir::find_codex_home;
 use codex_utils_oss::ensure_oss_provider_ready;
 use codex_utils_oss::get_default_model_for_oss_provider;
 use color_eyre::eyre::WrapErr;
@@ -1073,7 +1073,7 @@ pub async fn run_main(
         }
     }
 
-    let log_dir = crate::legacy_core::config::log_dir(&config)?;
+    let log_dir = config.log_dir.clone();
     std::fs::create_dir_all(&log_dir)?;
     // Open (or create) your log file, appending to it.
     let mut log_file_opts = OpenOptions::new();

codex-rs/tui/src/main.rs

@@ -1,5 +1,4 @@
 use clap::Parser;
-use codex_app_server_client::legacy_core;
 use codex_arg0::Arg0DispatchPaths;
 use codex_arg0::arg0_dispatch_or_else;
 use codex_config::LoaderOverrides;
@@ -8,6 +7,7 @@ use codex_tui::Cli;
 use codex_tui::ExitReason;
 use codex_tui::run_main;
 use codex_utils_cli::CliConfigOverrides;
+use codex_utils_cli::resume_command;
 use supports_color::Stream;
 
 fn format_exit_messages(exit_info: AppExitInfo, color_enabled: bool) -> Vec<String> {
@@ -22,9 +22,7 @@ fn format_exit_messages(exit_info: AppExitInfo, color_enabled: bool) -> Vec<Stri
         lines.push(token_usage.to_string());
     }
 
-    if let Some(resume_cmd) =
-        legacy_core::util::resume_command(/*thread_name*/ None, thread_id)
-    {
+    if let Some(resume_cmd) = resume_command(/*thread_name*/ None, thread_id) {
         let command = if color_enabled {
             format!("\u{1b}[36m{resume_cmd}\u{1b}[39m")
         } else {

codex-rs/tui/src/session_log.rs

@@ -88,10 +88,7 @@ pub(crate) fn maybe_init(config: &Config) {
     let path = if let Ok(path) = std::env::var("CODEX_TUI_SESSION_LOG_PATH") {
         PathBuf::from(path)
     } else {
-        let mut p = match crate::legacy_core::config::log_dir(config) {
-            Ok(dir) => dir,
-            Err(_) => std::env::temp_dir(),
-        };
+        let mut p = config.log_dir.clone();
         let filename = format!(
             "session-{}.jsonl",
             chrono::Utc::now().format("%Y%m%dT%H%M%SZ")