Chore: add cmd related info to exec approval request (#9659)

### Summary
We now rely purely on `item/commandExecution/requestApproval` item to
render pending approval in VSCE and app. With v2 approach, it does not
include the actual cmd that it is attempting and therefore we can only
use `proposedExecpolicyAmendment` to render which can be incomplete.

### Reproduce
* Add `prefix_rule(pattern=["echo"], decision="prompt")` to your
`~/.codex/rules.default.rules`.
* Ask to `Run  echo "approval-test" please` in VSCE or app. 
* The pending approval protal does show up but with no content

#### Example screenshot
<img width="3434" height="3648" alt="Screenshot 2026-01-21 at 8 23
25 PM"
src="https://github.com/user-attachments/assets/75644837-21f1-40f8-8b02-858d361ff817"
/>

#### Sample output
```
  {"method":"item/commandExecution/requestApproval","id":0,"params":{
    "threadId":"019be439-5a90-7600-a7ea-2d2dcc50302a",
    "turnId":"0",
    "itemId":"call_usgnQ4qEX5U9roNdjT7fPzhb",
    "reason":"`/bin/zsh -lc 'echo \"testing\"'` requires approval by policy",
    "proposedExecpolicyAmendment":null
  }}

```

### Fix
Inlude `command` string, `cwd` and `command_actions` in
`CommandExecutionRequestApprovalParams` so that consumers can display
the correct command instead of relying on exec policy output.

codex-rs/app-server-protocol/src/protocol/v2.rs

@@ -2263,6 +2263,18 @@ pub struct CommandExecutionRequestApprovalParams {
     pub item_id: String,
     /// Optional explanatory reason (e.g. request for network access).
     pub reason: Option<String>,
+    /// The command to be executed.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub command: Option<String>,
+    /// The command's working directory.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub cwd: Option<PathBuf>,
+    /// Best-effort parsed command actions for friendly display.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    #[ts(optional)]
+    pub command_actions: Option<Vec<CommandAction>>,
     /// Optional proposed execpolicy amendment to allow similar commands without prompting.
     pub proposed_execpolicy_amendment: Option<ExecPolicyAmendment>,
 }