Skip inactive TUI threads without pending user interaction (#35525)

## What changed

Only collect buffered requests from inactive threads whose event store reports
pending user input or approval. This keeps unrelated requests from being
considered when pending interactions are surfaced after leaving a side
conversation.

## Testing

Extend the side-conversation routing test with an unrelated dynamic tool request
and verify that only the pending subagent approval is selected.

GitOrigin-RevId: 388968277bde34bedc43187c1d1746d76166131e

codex-rs/tui/src/app/tests.rs

@@ -2961,6 +2961,8 @@ async fn side_defers_subagent_approval_overlay_until_side_exits() -> Result<()>
         ThreadId::from_string("00000000-0000-0000-0000-000000000022").expect("valid thread");
     let agent_thread_id =
         ThreadId::from_string("00000000-0000-0000-0000-000000000033").expect("valid thread");
+    let quiet_thread_id =
+        ThreadId::from_string("00000000-0000-0000-0000-000000000044").expect("valid thread");
 
     app.primary_thread_id = Some(main_thread_id);
     app.active_thread_id = Some(side_thread_id);
@@ -2986,14 +2988,27 @@ async fn side_defers_subagent_approval_overlay_until_side_exits() -> Result<()>
         /*is_closed*/ false,
     );
 
-    app.enqueue_thread_request(
+    let pending_approval = exec_approval_request(
         agent_thread_id,
-        exec_approval_request(
-            agent_thread_id,
-            "turn-approval",
-            "call-approval",
-            /*approval_id*/ None,
-        ),
+        "turn-approval",
+        "call-approval",
+        /*approval_id*/ None,
+    );
+    app.enqueue_thread_request(agent_thread_id, pending_approval.clone())
+        .await?;
+    app.enqueue_thread_request(
+        quiet_thread_id,
+        ServerRequest::DynamicToolCall {
+            request_id: AppServerRequestId::Integer(99),
+            params: codex_app_server_protocol::DynamicToolCallParams {
+                thread_id: quiet_thread_id.to_string(),
+                turn_id: "turn-quiet".to_string(),
+                call_id: "call-quiet".to_string(),
+                namespace: None,
+                tool: "ignored-tool".to_string(),
+                arguments: serde_json::json!({}),
+            },
+        },
     )
     .await?;
 
@@ -3005,6 +3020,10 @@ async fn side_defers_subagent_approval_overlay_until_side_exits() -> Result<()>
 
     app.side_threads.remove(&side_thread_id);
     app.active_thread_id = Some(main_thread_id);
+    assert_eq!(
+        app.pending_inactive_thread_requests().await,
+        vec![(agent_thread_id, pending_approval)]
+    );
     app.surface_pending_inactive_thread_interactive_requests()
         .await?;
 

codex-rs/tui/src/app/thread_routing.rs

@@ -389,6 +389,9 @@ impl App {
             }
 
             let store = store.lock().await;
+            if store.side_parent_pending_status().is_none() {
+                continue;
+            }
             requests.extend(
                 store
                     .pending_replay_requests()