Add PermissionRequest hooks support (#17563)

## Why

We need `PermissionRequest` hook support!

Also addresses:
- https://github.com/openai/codex/issues/16301
- run a script on Hook to do things like play a sound to draw attention
but actually no-op so user can still approve
- can omit the `decision` object from output or just have the script
exit 0 and print nothing
- https://github.com/openai/codex/issues/15311
  - let the script approve/deny on its own
  - external UI what will run on Hook and relay decision back to codex


## Reviewer Note

There's a lot of plumbing for the new hook, key files to review are:
- New hook added in `codex-rs/hooks/src/events/permission_request.rs`
- Wiring for network approvals
`codex-rs/core/src/tools/network_approval.rs`
- Wiring for tool orchestrator `codex-rs/core/src/tools/orchestrator.rs`
- Wiring for execve
`codex-rs/core/src/tools/runtimes/shell/unix_escalation.rs`

## What

- Wires shell, unified exec, and network approval prompts into the
`PermissionRequest` hook flow.
- Lets hooks allow or deny approval prompts; quiet or invalid hooks fall
back to the normal approval path.
- Uses `tool_input.description` for user-facing context when it helps:
  - shell / `exec_command`: the request justification, when present
  - network approvals: `network-access <domain>`
- Uses `tool_name: Bash` for shell, unified exec, and network approval
permission-request hooks.
- For network approvals, passes the originating command in
`tool_input.command` when there is a single owning call; otherwise falls
back to the synthetic `network-access ...` command.

<details>
<summary>Example `PermissionRequest` hook input for a shell
approval</summary>

```json
{
  "session_id": "<session-id>",
  "turn_id": "<turn-id>",
  "transcript_path": "/path/to/transcript.jsonl",
  "cwd": "/path/to/cwd",
  "hook_event_name": "PermissionRequest",
  "model": "gpt-5",
  "permission_mode": "default",
  "tool_name": "Bash",
  "tool_input": {
    "command": "rm -f /tmp/example"
  }
}
```

</details>

<details>
<summary>Example `PermissionRequest` hook input for an escalated
`exec_command` request</summary>

```json
{
  "session_id": "<session-id>",
  "turn_id": "<turn-id>",
  "transcript_path": "/path/to/transcript.jsonl",
  "cwd": "/path/to/cwd",
  "hook_event_name": "PermissionRequest",
  "model": "gpt-5",
  "permission_mode": "default",
  "tool_name": "Bash",
  "tool_input": {
    "command": "cp /tmp/source.json /Users/alice/export/source.json",
    "description": "Need to copy a generated file outside the workspace"
  }
}
```

</details>

<details>
<summary>Example `PermissionRequest` hook input for a network
approval</summary>

```json
{
  "session_id": "<session-id>",
  "turn_id": "<turn-id>",
  "transcript_path": "/path/to/transcript.jsonl",
  "cwd": "/path/to/cwd",
  "hook_event_name": "PermissionRequest",
  "model": "gpt-5",
  "permission_mode": "default",
  "tool_name": "Bash",
  "tool_input": {
    "command": "curl http://codex-network-test.invalid",
    "description": "network-access http://codex-network-test.invalid"
  }
}
```

</details>

## Follow-ups

- Implement the `PermissionRequest` semantics for `updatedInput`,
`updatedPermissions`, `interrupt`, and suggestions /
`permission_suggestions`
- Add `PermissionRequest` support for the `request_permissions` tool
path

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/core/src/hook_runtime.rs

@@ -4,6 +4,9 @@ use std::time::Duration;
 
 use codex_analytics::HookRunFact;
 use codex_analytics::build_track_events_context;
+use codex_hooks::PermissionRequestDecision;
+use codex_hooks::PermissionRequestOutcome;
+use codex_hooks::PermissionRequestRequest;
 use codex_hooks::PostToolUseOutcome;
 use codex_hooks::PostToolUseRequest;
 use codex_hooks::PreToolUseOutcome;
@@ -31,6 +34,7 @@ use serde_json::Value;
 use crate::codex::Session;
 use crate::codex::TurnContext;
 use crate::event_mapping::parse_turn_item;
+use crate::tools::sandboxing::PermissionRequestPayload;
 
 pub(crate) struct HookRuntimeOutcome {
     pub should_stop: bool,
@@ -153,6 +157,39 @@ pub(crate) async fn run_pre_tool_use_hooks(
     if should_block { block_reason } else { None }
 }
 
+// PermissionRequest hooks share the same preview/start/completed event flow as
+// other hook types, but they return an optional decision instead of mutating
+// tool input or post-run state.
+pub(crate) async fn run_permission_request_hooks(
+    sess: &Arc<Session>,
+    turn_context: &Arc<TurnContext>,
+    run_id_suffix: &str,
+    payload: PermissionRequestPayload,
+) -> Option<PermissionRequestDecision> {
+    let request = PermissionRequestRequest {
+        session_id: sess.conversation_id,
+        turn_id: turn_context.sub_id.clone(),
+        cwd: turn_context.cwd.to_path_buf(),
+        transcript_path: sess.hook_transcript_path().await,
+        model: turn_context.model_info.slug.clone(),
+        permission_mode: hook_permission_mode(turn_context),
+        tool_name: payload.tool_name,
+        run_id_suffix: run_id_suffix.to_string(),
+        command: payload.command,
+        description: payload.description,
+    };
+    let preview_runs = sess.hooks().preview_permission_request(&request);
+    emit_hook_started_events(sess, turn_context, preview_runs).await;
+
+    let PermissionRequestOutcome {
+        hook_events,
+        decision,
+    } = sess.hooks().run_permission_request(request).await;
+    emit_hook_completed_events(sess, turn_context, hook_events).await;
+
+    decision
+}
+
 pub(crate) async fn run_post_tool_use_hooks(
     sess: &Arc<Session>,
     turn_context: &Arc<TurnContext>,
@@ -390,6 +427,7 @@ fn hook_run_analytics_payload(
 fn hook_run_metric_tags(run: &HookRunSummary) -> [(&'static str, &'static str); 3] {
     let hook_name = match run.event_name {
         HookEventName::PreToolUse => "PreToolUse",
+        HookEventName::PermissionRequest => "PermissionRequest",
         HookEventName::PostToolUse => "PostToolUse",
         HookEventName::SessionStart => "SessionStart",
         HookEventName::UserPromptSubmit => "UserPromptSubmit",