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/thread-manager-sample/src/main.rs

@@ -227,6 +227,7 @@ fn new_config(model: Option<String>, arg0_paths: Arg0DispatchPaths) -> anyhow::R
         terminal_resize_reflow: TerminalResizeReflowConfig::default(),
         tui_keymap: TuiKeymap::default(),
         tui_session_picker_view: SessionPickerViewMode::Dense,
+        tui_resume_cwd: None,
         tui_vim_mode_default: false,
         cwd: cwd.clone(),
         workspace_roots: vec![cwd],