Add dev message upon review out (#3758)

Proposal: We want to record a dev message like so:

```
{
      "type": "message",
      "role": "user",
      "content": [
        {
          "type": "input_text",
          "text": "<user_action>
  <context>User initiated a review task. Here's the full review output from reviewer model. User may select one or more comments to resolve.</context>
  <action>review</action>
  <results>
  {findings_str}
  </results>
</user_action>"
        }
      ]
    },
```

Without showing in the chat transcript.

Rough idea, but it fixes issue where the user finishes a review thread,
and asks the parent "fix the rest of the review issues" thinking that
the parent knows about it.

### Question: Why not a tool call?

Because the agent didn't make the call, it was a human. + we haven't
implemented sub-agents yet, and we'll need to think about the way we
represent these human-led tool calls for the agent.

codex-rs/core/src/codex.rs

@@ -11,6 +11,7 @@ use std::time::Duration;
 use crate::AuthManager;
 use crate::client_common::REVIEW_PROMPT;
 use crate::event_mapping::map_response_item_to_event_messages;
+use crate::review_format::format_review_findings_block;
 use async_channel::Receiver;
 use async_channel::Sender;
 use codex_apply_patch::ApplyPatchAction;
@@ -3259,7 +3260,8 @@ fn convert_call_tool_result_to_function_call_output_payload(
     }
 }
 
-/// Emits an ExitedReviewMode Event with optional ReviewOutput.
+/// Emits an ExitedReviewMode Event with optional ReviewOutput,
+/// and records a developer message with the review output.
 async fn exit_review_mode(
     session: Arc<Session>,
     task_sub_id: String,
@@ -3267,9 +3269,50 @@ async fn exit_review_mode(
 ) {
     let event = Event {
         id: task_sub_id,
-        msg: EventMsg::ExitedReviewMode(ExitedReviewModeEvent { review_output }),
+        msg: EventMsg::ExitedReviewMode(ExitedReviewModeEvent {
+            review_output: review_output.clone(),
+        }),
     };
     session.send_event(event).await;
+
+    let mut user_message = String::new();
+    if let Some(out) = review_output {
+        let mut findings_str = String::new();
+        let text = out.overall_explanation.trim();
+        if !text.is_empty() {
+            findings_str.push_str(text);
+        }
+        if !out.findings.is_empty() {
+            let block = format_review_findings_block(&out.findings, None);
+            findings_str.push_str(&format!("\n{block}"));
+        }
+        user_message.push_str(&format!(
+            r#"<user_action>
+  <context>User initiated a review task. Here's the full review output from reviewer model. User may select one or more comments to resolve.</context>
+  <action>review</action>
+  <results>
+  {findings_str}
+  </results>
+</user_tool>
+"#));
+    } else {
+        user_message.push_str(r#"<user_action>
+  <context>User initiated a review task, but was interrupted. If user asks about this, tell them to re-initiate a review with `/review` and wait for it to complete.</context>
+  <action>review</action>
+  <results>
+  None.
+  </results>
+</user_tool>
+"#);
+    }
+
+    session
+        .record_conversation_items(&[ResponseItem::Message {
+            id: None,
+            role: "user".to_string(),
+            content: vec![ContentItem::InputText { text: user_message }],
+        }])
+        .await;
 }
 
 #[cfg(test)]

codex-rs/core/src/lib.rs

@@ -46,6 +46,7 @@ pub use model_provider_info::built_in_model_providers;
 pub use model_provider_info::create_oss_provider_with_base_url;
 mod conversation_manager;
 mod event_mapping;
+pub mod review_format;
 pub use codex_protocol::protocol::InitialHistory;
 pub use conversation_manager::ConversationManager;
 pub use conversation_manager::NewConversation;

codex-rs/core/src/review_format.rs

@@ -0,0 +1,55 @@
+use crate::protocol::ReviewFinding;
+
+// Note: We keep this module UI-agnostic. It returns plain strings that
+// higher layers (e.g., TUI) may style as needed.
+
+fn format_location(item: &ReviewFinding) -> String {
+    let path = item.code_location.absolute_file_path.display();
+    let start = item.code_location.line_range.start;
+    let end = item.code_location.line_range.end;
+    format!("{path}:{start}-{end}")
+}
+
+/// Format a full review findings block as plain text lines.
+///
+/// - When `selection` is `Some`, each item line includes a checkbox marker:
+///   "[x]" for selected items and "[ ]" for unselected. Missing indices
+///   default to selected.
+/// - When `selection` is `None`, the marker is omitted and a simple bullet is
+///   rendered ("- Title — path:start-end").
+pub fn format_review_findings_block(
+    findings: &[ReviewFinding],
+    selection: Option<&[bool]>,
+) -> String {
+    let mut lines: Vec<String> = Vec::new();
+
+    // Header
+    let header = if findings.len() > 1 {
+        "Full review comments:"
+    } else {
+        "Review comment:"
+    };
+    lines.push(header.to_string());
+
+    for (idx, item) in findings.iter().enumerate() {
+        lines.push(String::new());
+
+        let title = &item.title;
+        let location = format_location(item);
+
+        if let Some(flags) = selection {
+            // Default to selected if index is out of bounds.
+            let checked = flags.get(idx).copied().unwrap_or(true);
+            let marker = if checked { "[x]" } else { "[ ]" };
+            lines.push(format!("- {marker} {title} — {location}"));
+        } else {
+            lines.push(format!("- {title} — {location}"));
+        }
+
+        for body_line in item.body.lines() {
+            lines.push(format!("  {body_line}"));
+        }
+    }
+
+    lines.join("\n")
+}