Handle resuming/forking after compact (#3533)

We need to construct the history different when compact happens. For
this, we need to just consider the history after compact and convert
compact to a response item.

This needs to change and use `build_compact_history` when this #3446 is
merged.

codex-rs/protocol/src/protocol.rs

@@ -15,6 +15,7 @@ use crate::config_types::ReasoningSummary as ReasoningSummaryConfig;
 use crate::custom_prompts::CustomPrompt;
 use crate::mcp_protocol::ConversationId;
 use crate::message_history::HistoryEntry;
+use crate::models::ContentItem;
 use crate::models::ResponseItem;
 use crate::num_format::format_with_separators;
 use crate::parse_command::ParsedCommand;
@@ -862,26 +863,7 @@ impl InitialHistory {
             InitialHistory::Forked(items) => items.clone(),
         }
     }
-    pub fn get_response_items(&self) -> Vec<ResponseItem> {
-        match self {
-            InitialHistory::New => Vec::new(),
-            InitialHistory::Resumed(resumed) => resumed
-                .history
-                .iter()
-                .filter_map(|ri| match ri {
-                    RolloutItem::ResponseItem(item) => Some(item.clone()),
-                    _ => None,
-                })
-                .collect(),
-            InitialHistory::Forked(items) => items
-                .iter()
-                .filter_map(|ri| match ri {
-                    RolloutItem::ResponseItem(item) => Some(item.clone()),
-                    _ => None,
-                })
-                .collect(),
-        }
-    }
+
     pub fn get_event_msgs(&self) -> Option<Vec<EventMsg>> {
         match self {
             InitialHistory::New => None,
@@ -941,6 +923,18 @@ pub struct CompactedItem {
     pub message: String,
 }
 
+impl From<CompactedItem> for ResponseItem {
+    fn from(value: CompactedItem) -> Self {
+        ResponseItem::Message {
+            id: None,
+            role: "assistant".to_string(),
+            content: vec![ContentItem::OutputText {
+                text: value.message,
+            }],
+        }
+    }
+}
+
 #[derive(Serialize, Deserialize, Clone, Debug, TS)]
 pub struct TurnContextItem {
     pub cwd: PathBuf,