feat: include available decisions in command approval requests (#12758)

Command-approval clients currently infer which choices to show from
side-channel fields like `networkApprovalContext`,
`proposedExecpolicyAmendment`, and `additionalPermissions`. That makes
the request shape harder to evolve, and it forces each client to
replicate the server's heuristics instead of receiving the exact
decision list for the prompt.

This PR introduces a mapping between `CommandExecutionApprovalDecision`
and `codex_protocol::protocol::ReviewDecision`:

```rust
impl From<CoreReviewDecision> for CommandExecutionApprovalDecision {
    fn from(value: CoreReviewDecision) -> Self {
        match value {
            CoreReviewDecision::Approved => Self::Accept,
            CoreReviewDecision::ApprovedExecpolicyAmendment {
                proposed_execpolicy_amendment,
            } => Self::AcceptWithExecpolicyAmendment {
                execpolicy_amendment: proposed_execpolicy_amendment.into(),
            },
            CoreReviewDecision::ApprovedForSession => Self::AcceptForSession,
            CoreReviewDecision::NetworkPolicyAmendment {
                network_policy_amendment,
            } => Self::ApplyNetworkPolicyAmendment {
                network_policy_amendment: network_policy_amendment.into(),
            },
            CoreReviewDecision::Abort => Self::Cancel,
            CoreReviewDecision::Denied => Self::Decline,
        }
    }
}
```

And updates `CommandExecutionRequestApprovalParams` to have a new field:

```rust
available_decisions: Option<Vec<CommandExecutionApprovalDecision>>
```

when, if specified, should make it easier for clients to display an
appropriate list of options in the UI.

This makes it possible for `CoreShellActionProvider::prompt()` in
`unix_escalation.rs` to specify the `Vec<ReviewDecision>` directly,
adding support for `ApprovedForSession` when approving a skill script,
which was previously missing in the TUI.

Note this results in a significant change to `exec_options()` in
`approval_overlay.rs`, as the displayed options are now derived from
`available_decisions: &[ReviewDecision]`.

## What Changed

- Add `available_decisions` to
[`ExecApprovalRequestEvent`](https://github.com/openai/codex/blob/de00e932dd9801de0a4faac0519162099753f331/codex-rs/protocol/src/approvals.rs#L111-L175),
including helpers to derive the legacy default choices when older
senders omit the field.
- Map `codex_protocol::protocol::ReviewDecision` to app-server
`CommandExecutionApprovalDecision` and expose the ordered list as
experimental `availableDecisions` in
[`CommandExecutionRequestApprovalParams`](https://github.com/openai/codex/blob/de00e932dd9801de0a4faac0519162099753f331/codex-rs/app-server-protocol/src/protocol/v2.rs#L3798-L3807).
- Thread optional `available_decisions` through the core approval path
so Unix shell escalation can explicitly request `ApprovedForSession` for
session-scoped approvals instead of relying on client heuristics.
[`unix_escalation.rs`](https://github.com/openai/codex/blob/de00e932dd9801de0a4faac0519162099753f331/codex-rs/core/src/tools/runtimes/shell/unix_escalation.rs#L194-L214)
- Update the TUI approval overlay to build its buttons from the ordered
decision list, while preserving the legacy fallback when
`available_decisions` is missing.
- Update the app-server README, test client output, and generated schema
artifacts to document and surface the new field.

## Testing

- Add `approval_overlay.rs` coverage for explicit decision lists,
including the generic `ApprovedForSession` path and network approval
options.
- Update `chatwidget/tests.rs` and app-server protocol tests to populate
the new optional field and keep older event shapes working.

## Developers Docs

- If we document `item/commandExecution/requestApproval` on
[developers.openai.com/codex](https://developers.openai.com/codex), add
experimental `availableDecisions` as the preferred source of approval
choices and note that older servers may omit it.

codex-rs/app-server/README.md

@@ -710,7 +710,7 @@ Certain actions (shell commands or modifying files) may require explicit user ap
 Order of messages:
 
 1. `item/started` — shows the pending `commandExecution` item with `command`, `cwd`, and other fields so you can render the proposed action.
-2. `item/commandExecution/requestApproval` (request) — carries the same `itemId`, `threadId`, `turnId`, optionally `approvalId` (for subcommand callbacks), and `reason`. For normal command approvals, it also includes `command`, `cwd`, and `commandActions` for friendly display. When `initialize.params.capabilities.experimentalApi = true`, it may also include experimental `additionalPermissions` describing requested per-command sandbox access. For network-only approvals, those command fields may be omitted and `networkApprovalContext` is provided instead. Optional persistence hints may also be included via `proposedExecpolicyAmendment` and `proposedNetworkPolicyAmendments`.
+2. `item/commandExecution/requestApproval` (request) — carries the same `itemId`, `threadId`, `turnId`, optionally `approvalId` (for subcommand callbacks), and `reason`. For normal command approvals, it also includes `command`, `cwd`, and `commandActions` for friendly display. When `initialize.params.capabilities.experimentalApi = true`, it may also include experimental `additionalPermissions` describing requested per-command sandbox access. For network-only approvals, those command fields may be omitted and `networkApprovalContext` is provided instead. Optional persistence hints may also be included via `proposedExecpolicyAmendment` and `proposedNetworkPolicyAmendments`. Clients can prefer `availableDecisions` when present to render the exact set of choices the server wants to expose, while still falling back to the older heuristics if it is omitted.
 3. Client response — for example `{ "decision": "accept" }`, `{ "decision": "acceptForSession" }`, `{ "decision": { "acceptWithExecpolicyAmendment": { "execpolicy_amendment": [...] } } }`, `{ "decision": { "applyNetworkPolicyAmendment": { "network_policy_amendment": { "host": "example.com", "action": "allow" } } } }`, `{ "decision": "decline" }`, or `{ "decision": "cancel" }`.
 4. `item/completed` — final `commandExecution` item with `status: "completed" | "failed" | "declined"` and execution output. Render this as the authoritative result.
 

codex-rs/app-server/src/bespoke_event_handling.rs

@@ -332,6 +332,11 @@ pub(crate) async fn apply_bespoke_event_handling(
                 .note_permission_requested(&conversation_id.to_string())
                 .await;
             let approval_id_for_op = ev.effective_approval_id();
+            let available_decisions = ev
+                .effective_available_decisions()
+                .into_iter()
+                .map(CommandExecutionApprovalDecision::from)
+                .collect::<Vec<_>>();
             let ExecApprovalRequestEvent {
                 call_id,
                 approval_id,
@@ -428,6 +433,7 @@ pub(crate) async fn apply_bespoke_event_handling(
                         additional_permissions,
                         proposed_execpolicy_amendment: proposed_execpolicy_amendment_v2,
                         proposed_network_policy_amendments: proposed_network_policy_amendments_v2,
+                        available_decisions: Some(available_decisions),
                     };
                     let rx = outgoing
                         .send_request(ServerRequestPayload::CommandExecutionRequestApproval(

codex-rs/app-server/src/transport.rs

@@ -986,6 +986,7 @@ mod tests {
                         ),
                         proposed_execpolicy_amendment: None,
                         proposed_network_policy_amendments: None,
+                        available_decisions: None,
                     },
                 }),
             },
@@ -1047,6 +1048,7 @@ mod tests {
                         ),
                         proposed_execpolicy_amendment: None,
                         proposed_network_policy_amendments: None,
+                        available_decisions: None,
                     },
                 }),
             },