tui: plumb permission profile selection (#23708)

## Why

The named-profile `/permissions` picker needs a small TUI action path
that can select permission profiles without folding the menu UI and
profile metadata into the same review.

## What changed

- Carry permission-profile selections through the TUI app event flow.
- Persist selected profiles while preserving the existing approval
settings and guardrail prompts.
- Keep the legacy `/permissions` picker behavior in this layer; the
profile-mode menu stays in the follow-up PR.

## Stack

1. [#22931](https://github.com/openai/codex/pull/22931):
runtime/session/network propagation for active permission profiles.
2. **This PR**: TUI selection plumbing and guardrail flow.
3. [#21559](https://github.com/openai/codex/pull/21559): profile-aware
`/permissions` menu and custom profile display.

<img width="1632" height="1186" alt="image"
src="https://github.com/user-attachments/assets/69ddcd5e-b57c-468d-8c1d-246916323c15"
/>

## Validation

- `git diff --cached --check` before commit.
- Full test run skipped at the user request while pushing the split
stack.

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

@@ -297,7 +297,10 @@ impl ChatWidget {
                         &[],
                     );
                     self.app_event_tx
-                        .send(AppEvent::BeginWindowsSandboxElevatedSetup { preset });
+                        .send(AppEvent::BeginWindowsSandboxElevatedSetup {
+                            preset,
+                            profile_selection: None,
+                        });
                 }
                 #[cfg(not(target_os = "windows"))]
                 {