Handle cancelling/aborting while processing a turn (#5543)

Currently we collect all all turn items in a vector, then we add it to
the history on success. This result in losing those items on errors
including aborting `ctrl+c`.

This PR:
- Adds the ability for the tool call to handle cancellation
- bubble the turn items up to where we are recording this info

Admittedly, this logic is an ad-hoc logic that doesn't handle a lot of
error edge cases. The right thing to do is recording to the history on
the spot as `items`/`tool calls output` come. However, this isn't
possible because of having different `task_kind` that has different
`conversation_histories`. The `try_run_turn` has no idea what thread are
we using. We cannot also pass an `arc` to the `conversation_histories`
because it's a private element of `state`.

That's said, `abort` is the most common case and we should cover it
until we remove `task kind`

codex-rs/core/src/response_processing.rs

@@ -0,0 +1,112 @@
+use crate::codex::Session;
+use crate::conversation_history::ConversationHistory;
+use codex_protocol::models::FunctionCallOutputPayload;
+use codex_protocol::models::ResponseInputItem;
+use codex_protocol::models::ResponseItem;
+use tracing::warn;
+
+/// Process streamed `ResponseItem`s from the model into the pair of:
+/// - items we should record in conversation history; and
+/// - `ResponseInputItem`s to send back to the model on the next turn.
+pub(crate) async fn process_items(
+    processed_items: Vec<crate::codex::ProcessedResponseItem>,
+    is_review_mode: bool,
+    review_thread_history: &mut ConversationHistory,
+    sess: &Session,
+) -> (Vec<ResponseInputItem>, Vec<ResponseItem>) {
+    let mut items_to_record_in_conversation_history = Vec::<ResponseItem>::new();
+    let mut responses = Vec::<ResponseInputItem>::new();
+    for processed_response_item in processed_items {
+        let crate::codex::ProcessedResponseItem { item, response } = processed_response_item;
+        match (&item, &response) {
+            (ResponseItem::Message { role, .. }, None) if role == "assistant" => {
+                // If the model returned a message, we need to record it.
+                items_to_record_in_conversation_history.push(item);
+            }
+            (
+                ResponseItem::LocalShellCall { .. },
+                Some(ResponseInputItem::FunctionCallOutput { call_id, output }),
+            ) => {
+                items_to_record_in_conversation_history.push(item);
+                items_to_record_in_conversation_history.push(ResponseItem::FunctionCallOutput {
+                    call_id: call_id.clone(),
+                    output: output.clone(),
+                });
+            }
+            (
+                ResponseItem::FunctionCall { .. },
+                Some(ResponseInputItem::FunctionCallOutput { call_id, output }),
+            ) => {
+                items_to_record_in_conversation_history.push(item);
+                items_to_record_in_conversation_history.push(ResponseItem::FunctionCallOutput {
+                    call_id: call_id.clone(),
+                    output: output.clone(),
+                });
+            }
+            (
+                ResponseItem::CustomToolCall { .. },
+                Some(ResponseInputItem::CustomToolCallOutput { call_id, output }),
+            ) => {
+                items_to_record_in_conversation_history.push(item);
+                items_to_record_in_conversation_history.push(ResponseItem::CustomToolCallOutput {
+                    call_id: call_id.clone(),
+                    output: output.clone(),
+                });
+            }
+            (
+                ResponseItem::FunctionCall { .. },
+                Some(ResponseInputItem::McpToolCallOutput { call_id, result }),
+            ) => {
+                items_to_record_in_conversation_history.push(item);
+                let output = match result {
+                    Ok(call_tool_result) => {
+                        crate::codex::convert_call_tool_result_to_function_call_output_payload(
+                            call_tool_result,
+                        )
+                    }
+                    Err(err) => FunctionCallOutputPayload {
+                        content: err.clone(),
+                        success: Some(false),
+                    },
+                };
+                items_to_record_in_conversation_history.push(ResponseItem::FunctionCallOutput {
+                    call_id: call_id.clone(),
+                    output,
+                });
+            }
+            (
+                ResponseItem::Reasoning {
+                    id,
+                    summary,
+                    content,
+                    encrypted_content,
+                },
+                None,
+            ) => {
+                items_to_record_in_conversation_history.push(ResponseItem::Reasoning {
+                    id: id.clone(),
+                    summary: summary.clone(),
+                    content: content.clone(),
+                    encrypted_content: encrypted_content.clone(),
+                });
+            }
+            _ => {
+                warn!("Unexpected response item: {item:?} with response: {response:?}");
+            }
+        };
+        if let Some(response) = response {
+            responses.push(response);
+        }
+    }
+
+    // Only attempt to take the lock if there is something to record.
+    if !items_to_record_in_conversation_history.is_empty() {
+        if is_review_mode {
+            review_thread_history.record_items(items_to_record_in_conversation_history.iter());
+        } else {
+            sess.record_conversation_items(&items_to_record_in_conversation_history)
+                .await;
+        }
+    }
+    (responses, items_to_record_in_conversation_history)
+}