chore: unify conversation with thread name (#8830)

Done and verified by Codex + refactor feature of RustRover

codex-rs/core/src/codex_thread.rs

@@ -0,0 +1,44 @@
+use crate::agent::AgentStatus;
+use crate::codex::Codex;
+use crate::error::Result as CodexResult;
+use crate::protocol::Event;
+use crate::protocol::Op;
+use crate::protocol::Submission;
+use std::path::PathBuf;
+
+pub struct CodexThread {
+    codex: Codex,
+    rollout_path: PathBuf,
+}
+
+/// Conduit for the bidirectional stream of messages that compose a thread
+/// (formerly called a conversation) in Codex.
+impl CodexThread {
+    pub(crate) fn new(codex: Codex, rollout_path: PathBuf) -> Self {
+        Self {
+            codex,
+            rollout_path,
+        }
+    }
+
+    pub async fn submit(&self, op: Op) -> CodexResult<String> {
+        self.codex.submit(op).await
+    }
+
+    /// Use sparingly: this is intended to be removed soon.
+    pub async fn submit_with_id(&self, sub: Submission) -> CodexResult<()> {
+        self.codex.submit_with_id(sub).await
+    }
+
+    pub async fn next_event(&self) -> CodexResult<Event> {
+        self.codex.next_event().await
+    }
+
+    pub async fn agent_status(&self) -> AgentStatus {
+        self.codex.agent_status().await
+    }
+
+    pub fn rollout_path(&self) -> PathBuf {
+        self.rollout_path.clone()
+    }
+}