Let users remember the working directory for resumed sessions (#33950)

## What changed

- Add `tui.resume_cwd` with `current` and `session` modes for resume and fork flows.
- Let users persist either mode directly from the working-directory prompt, while preserving one-time choices when no preference is configured.
- Apply the preference consistently during startup and in-app resume, honor explicit `--cd` overrides, and reject unsupported or unavailable directory choices with a clear error.

## Testing

- Cover configuration parsing and persistence, prompt behavior, startup and in-app flows, session metadata fallback, and remote workspace constraints.

GitOrigin-RevId: 7bf144c4b8c55bdb868cc8a71caf397c7740451a

codex-rs/core/src/config/config_tests.rs

@@ -55,6 +55,7 @@ use codex_config::types::NotificationMethod;
 use codex_config::types::Notifications;
 use codex_config::types::OtelConfigToml;
 use codex_config::types::OtelExporterKind;
+use codex_config::types::ResumeCwdMode;
 use codex_config::types::SandboxWorkspaceWrite;
 use codex_config::types::SessionPickerViewMode;
 use codex_config::types::SkillsConfig;
@@ -946,6 +947,7 @@ fn config_toml_deserializes_model_availability_nux() {
             pet: None,
             pet_anchor: TuiPetAnchor::Composer,
             session_picker_view: None,
+            resume_cwd: None,
             keymap: TuiKeymap::default(),
             model_availability_nux: ModelAvailabilityNuxConfig {
                 shown_count: HashMap::from([
@@ -3684,6 +3686,19 @@ session_picker_view = "dense"
     );
 }
 
+#[test]
+fn tui_resume_cwd_deserializes_from_toml() {
+    let cfg = r#"
+[tui]
+resume_cwd = "current"
+"#;
+    let parsed = toml::from_str::<ConfigToml>(cfg).expect("TOML deserialization should succeed");
+    assert_eq!(
+        parsed.tui.as_ref().and_then(|t| t.resume_cwd),
+        Some(ResumeCwdMode::Current),
+    );
+}
+
 #[test]
 fn tui_pet_deserializes_from_toml() {
     let cfg = r#"
@@ -3785,6 +3800,7 @@ fn tui_config_missing_notifications_field_defaults_to_enabled() {
             pet: None,
             pet_anchor: TuiPetAnchor::Composer,
             session_picker_view: None,
+            resume_cwd: None,
             keymap: TuiKeymap::default(),
             model_availability_nux: ModelAvailabilityNuxConfig::default(),
             terminal_resize_reflow_max_rows: None,
@@ -3967,6 +3983,35 @@ async fn runtime_config_resolves_session_picker_view_default_and_override() {
     );
 }
 
+#[tokio::test]
+async fn runtime_config_resolves_resume_cwd_default_and_override() {
+    let cfg = Config::load_from_base_config_with_overrides(
+        ConfigToml::default(),
+        ConfigOverrides::default(),
+        tempdir().expect("tempdir").abs(),
+    )
+    .await
+    .expect("load default config");
+
+    assert_eq!(cfg.tui_resume_cwd, None);
+
+    let cfg = Config::load_from_base_config_with_overrides(
+        ConfigToml {
+            tui: Some(Tui {
+                resume_cwd: Some(ResumeCwdMode::Session),
+                ..Default::default()
+            }),
+            ..Default::default()
+        },
+        ConfigOverrides::default(),
+        tempdir().expect("tempdir").abs(),
+    )
+    .await
+    .expect("load root override config");
+
+    assert_eq!(cfg.tui_resume_cwd, Some(ResumeCwdMode::Session));
+}
+
 #[tokio::test]
 async fn test_sandbox_config_parsing() {
     let sandbox_full_access = r#"

codex-rs/core/src/config/edit.rs

@@ -3,6 +3,7 @@ use crate::path_utils::write_atomically;
 use anyhow::Context;
 use codex_config::CONFIG_TOML_FILE;
 use codex_config::types::McpServerConfig;
+use codex_config::types::ResumeCwdMode;
 use codex_config::types::SessionPickerViewMode;
 use codex_config::types::ToolSuggestDisabledTool;
 use codex_features::FEATURES;
@@ -962,6 +963,14 @@ impl ConfigEditsBuilder {
         self
     }
 
+    pub fn set_resume_cwd(mut self, mode: ResumeCwdMode) -> Self {
+        self.edits.push(ConfigEdit::SetPath {
+            segments: vec!["tui".to_string(), "resume_cwd".to_string()],
+            value: value(mode.as_str()),
+        });
+        self
+    }
+
     pub fn with_edits<I>(mut self, edits: I) -> Self
     where
         I: IntoIterator<Item = ConfigEdit>,

codex-rs/core/src/config/mod.rs

@@ -43,6 +43,7 @@ use codex_config::types::MemoriesConfig;
 use codex_config::types::ModelAvailabilityNuxConfig;
 use codex_config::types::Notice;
 use codex_config::types::OAuthCredentialsStoreMode;
+use codex_config::types::ResumeCwdMode;
 use codex_config::types::SessionPickerViewMode;
 use codex_config::types::ToolSuggestConfig;
 use codex_config::types::ToolSuggestDisabledTool;
@@ -789,6 +790,10 @@ pub struct Config {
     /// Preferred layout for resume/fork session picker results.
     pub tui_session_picker_view: SessionPickerViewMode,
 
+    /// Working directory to use when resuming or forking a session.
+    /// When unset, prompt if the current and session directories differ.
+    pub tui_resume_cwd: Option<ResumeCwdMode>,
+
     /// Terminal resize-reflow tuning knobs.
     pub terminal_resize_reflow: TerminalResizeReflowConfig,
 
@@ -4118,6 +4123,7 @@ impl Config {
                 .as_ref()
                 .and_then(|t| t.session_picker_view)
                 .unwrap_or_default(),
+            tui_resume_cwd: cfg.tui.as_ref().and_then(|t| t.resume_cwd),
             terminal_resize_reflow,
             tui_keymap: cfg
                 .tui