feat: make interrupt state not final for multi-agents (#13850)

Make `interrupted` an agent state and make it not final. As a result, a
`wait` won't return on an interrupted agent and no notification will be
send to the parent agent.

The rationals are:
* If a user interrupt a sub-agent for any reason, you don't want the
parent agent to instantaneously ask the sub-agent to restart
* If a parent agent interrupt a sub-agent, no need to add a noisy
notification in the parent agen

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

@@ -4542,6 +4542,7 @@ pub enum CollabAgentToolCallStatus {
 pub enum CollabAgentStatus {
     PendingInit,
     Running,
+    Interrupted,
     Completed,
     Errored,
     Shutdown,
@@ -4567,6 +4568,10 @@ impl From<CoreAgentStatus> for CollabAgentState {
                 status: CollabAgentStatus::Running,
                 message: None,
             },
+            CoreAgentStatus::Interrupted => Self {
+                status: CollabAgentStatus::Interrupted,
+                message: None,
+            },
             CoreAgentStatus::Completed(message) => Self {
                 status: CollabAgentStatus::Completed,
                 message,
@@ -5886,6 +5891,17 @@ mod tests {
         absolute_path("readable")
     }
 
+    #[test]
+    fn collab_agent_state_maps_interrupted_status() {
+        assert_eq!(
+            CollabAgentState::from(CoreAgentStatus::Interrupted),
+            CollabAgentState {
+                status: CollabAgentStatus::Interrupted,
+                message: None,
+            }
+        );
+    }
+
     #[test]
     fn command_execution_request_approval_rejects_relative_additional_permission_paths() {
         let err = serde_json::from_value::<CommandExecutionRequestApprovalParams>(json!({