Enable memories for paginated threads (#34386)

## Why

Paginated threads keep metadata updates in SQLite, while their rollout retains the initial `memory_mode`. Reconciliation could therefore overwrite the current setting with a stale value, and memory processing excluded these threads entirely.

## What changed

- Include paginated threads in stage 1 memory job selection and global memory output lookup.
- Preserve the SQLite `memory_mode` when reconciling or backfilling an existing paginated thread, while continuing to seed missing rows and restore legacy threads from rollouts.
- Omit `memory_mode` alongside Git metadata when flushing resumed paginated history.

## Testing

Added coverage for preserving disabled memory mode during reconciliation and backfill, selecting eligible paginated threads, and omitting initial metadata on paginated resume.

GitOrigin-RevId: 2a6e16068e69680728757fbec27aeefae45b8110

codex-rs/rollout/src/state_db_tests.rs

@@ -10,6 +10,7 @@ use codex_protocol::protocol::EventMsg;
 use codex_protocol::protocol::RolloutLine;
 use codex_protocol::protocol::SessionMeta;
 use codex_protocol::protocol::SessionMetaLine;
+use codex_protocol::protocol::ThreadHistoryMode;
 use codex_protocol::protocol::UserMessageEvent;
 use pretty_assertions::assert_eq;
 use std::path::Path;
@@ -111,7 +112,8 @@ async fn try_init_times_out_waiting_for_stuck_startup_backfill() -> anyhow::Resu
 async fn reconcile_rollout_preserves_existing_explicit_title() -> anyhow::Result<()> {
     let home = TempDir::new().expect("temp dir");
     let thread_id = ThreadId::new();
-    let rollout_path = write_rollout_with_user_message(home.path(), thread_id, "Hey")?;
+    let rollout_path =
+        write_rollout_with_user_message(home.path(), thread_id, "Hey", ThreadHistoryMode::Legacy)?;
     let runtime =
         codex_state::StateRuntime::init(home.path().to_path_buf(), "test-provider".to_string())
             .await?;
@@ -145,10 +147,59 @@ async fn reconcile_rollout_preserves_existing_explicit_title() -> anyhow::Result
     Ok(())
 }
 
+#[tokio::test]
+async fn reconcile_rollout_preserves_existing_paginated_memory_mode() -> anyhow::Result<()> {
+    let home = TempDir::new().expect("temp dir");
+    let thread_id = ThreadId::new();
+    let rollout_path = write_rollout_with_user_message(
+        home.path(),
+        thread_id,
+        "Hey",
+        ThreadHistoryMode::Paginated,
+    )?;
+    let runtime =
+        codex_state::StateRuntime::init(home.path().to_path_buf(), "test-provider".to_string())
+            .await?;
+
+    reconcile_rollout(
+        Some(runtime.as_ref()),
+        rollout_path.as_path(),
+        "test-provider",
+        /*builder*/ None,
+        &[],
+        /*archived_only*/ None,
+        /*new_thread_memory_mode*/ None,
+    )
+    .await;
+    assert!(
+        runtime
+            .set_thread_memory_mode(thread_id, "disabled")
+            .await?
+    );
+
+    reconcile_rollout(
+        Some(runtime.as_ref()),
+        rollout_path.as_path(),
+        "test-provider",
+        /*builder*/ None,
+        &[],
+        /*archived_only*/ None,
+        /*new_thread_memory_mode*/ None,
+    )
+    .await;
+
+    assert_eq!(
+        runtime.get_thread_memory_mode(thread_id).await?.as_deref(),
+        Some("disabled")
+    );
+    Ok(())
+}
+
 fn write_rollout_with_user_message(
     home: &Path,
     thread_id: ThreadId,
     message: &str,
+    history_mode: ThreadHistoryMode,
 ) -> anyhow::Result<std::path::PathBuf> {
     let dir = home.join("sessions/2026/06/01");
     std::fs::create_dir_all(dir.as_path())?;
@@ -177,7 +228,7 @@ fn write_rollout_with_user_message(
                     dynamic_tools: None,
                     selected_capability_roots: Vec::new(),
                     memory_mode: None,
-                    history_mode: Default::default(),
+                    history_mode,
                     history_base: None,
                     subagent_history_start_ordinal: None,
                     multi_agent_version: None,