fix: shell snapshot clean-up (#9155)

Clean all shell snapshot files corresponding to sessions that have not
been updated in 7 days
Those files should never leak. The only known cases were it can leak are
during non graceful interrupt of the process (`kill -9, `panic`, OS
crash, ...)

codex-rs/core/src/rollout/recorder.rs

@@ -1,10 +1,12 @@
 //! Persist Codex session rollouts (.jsonl) so sessions can be replayed or inspected later.
 
 use std::fs::File;
+use std::fs::FileTimes;
 use std::fs::{self};
 use std::io::Error as IoError;
 use std::path::Path;
 use std::path::PathBuf;
+use std::time::SystemTime;
 
 use codex_protocol::ThreadId;
 use serde_json::Value;
@@ -151,14 +153,17 @@ impl RolloutRecorder {
                     }),
                 )
             }
-            RolloutRecorderParams::Resume { path } => (
-                tokio::fs::OpenOptions::new()
-                    .append(true)
-                    .open(&path)
-                    .await?,
-                path,
-                None,
-            ),
+            RolloutRecorderParams::Resume { path } => {
+                touch_rollout_file(&path)?;
+                (
+                    tokio::fs::OpenOptions::new()
+                        .append(true)
+                        .open(&path)
+                        .await?,
+                    path,
+                    None,
+                )
+            }
         };
 
         // Clone the cwd for the spawned task to collect git info asynchronously
@@ -343,6 +348,13 @@ fn create_log_file(config: &Config, conversation_id: ThreadId) -> std::io::Resul
     })
 }
 
+fn touch_rollout_file(path: &Path) -> std::io::Result<()> {
+    let file = fs::OpenOptions::new().append(true).open(path)?;
+    let times = FileTimes::new().set_modified(SystemTime::now());
+    file.set_times(times)?;
+    Ok(())
+}
+
 async fn rollout_writer(
     file: tokio::fs::File,
     mut rx: mpsc::Receiver<RolloutCmd>,