fix: pretty-print the sandbox config in the TUI/exec modes (#1376)

Now that https://github.com/openai/codex/pull/1373 simplified the
sandbox config, we can print something much simpler in the TUI (and in
`codex exec`) to summarize the sandbox config.

Before:

![Screenshot 2025-06-24 at 5 45
52 PM](https://github.com/user-attachments/assets/b7633efb-a619-43e1-9abe-7bb0be2d0ec0)

With this change:

![Screenshot 2025-06-24 at 5 46
44 PM](https://github.com/user-attachments/assets/8d099bdd-a429-4796-a08d-70931d984e4f)

For reference, my `config.toml` contains:

```
[sandbox]
mode = "workspace-write"
writable_roots = ["/tmp", "/Users/mbolin/.pyenv/shims"]
```

Fixes https://github.com/openai/codex/issues/1248

codex-rs/tui/Cargo.toml

@@ -20,7 +20,11 @@ base64 = "0.22.1"
 clap = { version = "4", features = ["derive"] }
 codex-ansi-escape = { path = "../ansi-escape" }
 codex-core = { path = "../core" }
-codex-common = { path = "../common", features = ["cli", "elapsed"] }
+codex-common = { path = "../common", features = [
+    "cli",
+    "elapsed",
+    "sandbox_summary",
+] }
 codex-linux-sandbox = { path = "../linux-sandbox" }
 codex-login = { path = "../login" }
 color-eyre = "0.6.3"

codex-rs/tui/src/history_cell.rs

@@ -6,6 +6,7 @@ use crate::text_formatting::format_and_truncate_tool_result;
 use base64::Engine;
 use codex_ansi_escape::ansi_escape_line;
 use codex_common::elapsed::format_duration;
+use codex_common::summarize_sandbox_policy;
 use codex_core::WireApi;
 use codex_core::config::Config;
 use codex_core::model_supports_reasoning_summaries;
@@ -152,7 +153,7 @@ impl HistoryCell {
                 ("model", config.model.clone()),
                 ("provider", config.model_provider_id.clone()),
                 ("approval", format!("{:?}", config.approval_policy)),
-                ("sandbox", format!("{:?}", config.sandbox_policy)),
+                ("sandbox", summarize_sandbox_policy(&config.sandbox_policy)),
             ];
             if config.model_provider.wire_api == WireApi::Responses
                 && model_supports_reasoning_summaries(&config.model)