feat(core) Persist request_permission data across turns (#14009)

## Summary
request_permissions flows should support persisting results for the
session.

Open Question: Still deciding if we need within-turn approvals - this
adds complexity but I could see it being useful

## Testing
- [x] Updated unit tests

---------

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

codex-rs/protocol/src/request_permissions.rs

@@ -4,6 +4,14 @@ use serde::Deserialize;
 use serde::Serialize;
 use ts_rs::TS;
 
+#[derive(Debug, Clone, Copy, Default, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "snake_case")]
+pub enum PermissionGrantScope {
+    #[default]
+    Turn,
+    Session,
+}
+
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
 pub struct RequestPermissionsArgs {
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -14,6 +22,8 @@ pub struct RequestPermissionsArgs {
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
 pub struct RequestPermissionsResponse {
     pub permissions: PermissionProfile,
+    #[serde(default)]
+    pub scope: PermissionGrantScope,
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]