add turn_id to exec approval request event

codex-rs/protocol/src/approvals.rs

@@ -36,6 +36,10 @@ impl SandboxRiskLevel {
 pub struct ExecApprovalRequestEvent {
     /// Identifier for the associated exec call, if available.
     pub call_id: String,
+    /// Turn ID that this command belongs to.
+    /// Uses `#[serde(default)]` for backwards compatibility.
+    #[serde(default)]
+    pub turn_id: String,
     /// The command to be executed.
     pub command: Vec<String>,
     /// The command's working directory.