Add sorting/backwardsCursor to thread/list and new thread/turns/list api (#17305)

To improve performance of UI loads from the app, add two main
improvements:
1. The `thread/list` api now gets a `sortDirection` request field and a
`backwardsCursor` to the response, which lets you paginate forwards and
backwards from a window. This lets you fetch the first few items to
display immediately while you paginate to fill in history, then can
paginate "backwards" on future loads to catch up with any changes since
the last UI load without a full reload of the entire data set.
2. Added a new `thread/turns/list` api which also has sortDirection and
backwardsCursor for the same behavior as `thread/list`, allowing you the
same small-fetch for immediate display followed by background fill-in
and resync catchup.

codex-rs/rollout/src/state_db.rs

@@ -1,10 +1,10 @@
 use crate::config::RolloutConfig;
 use crate::config::RolloutConfigView;
 use crate::list::Cursor;
+use crate::list::SortDirection;
 use crate::list::ThreadSortKey;
 use crate::metadata;
 use chrono::DateTime;
-use chrono::NaiveDateTime;
 use chrono::Utc;
 use codex_protocol::ThreadId;
 use codex_protocol::dynamic_tools::DynamicToolSpec;
@@ -18,7 +18,6 @@ use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
 use tracing::warn;
-use uuid::Uuid;
 
 /// Core-facing handle to the SQLite-backed state runtime.
 pub type StateDbHandle = Arc<codex_state::StateRuntime>;
@@ -117,21 +116,10 @@ async fn require_backfill_complete(
 
 fn cursor_to_anchor(cursor: Option<&Cursor>) -> Option<codex_state::Anchor> {
     let cursor = cursor?;
-    let value = serde_json::to_value(cursor).ok()?;
-    let cursor_str = value.as_str()?;
-    let (ts_str, id_str) = cursor_str.split_once('|')?;
-    if id_str.contains('|') {
-        return None;
-    }
-    let id = Uuid::parse_str(id_str).ok()?;
-    let ts = if let Ok(naive) = NaiveDateTime::parse_from_str(ts_str, "%Y-%m-%dT%H-%M-%S") {
-        DateTime::<Utc>::from_naive_utc_and_offset(naive, Utc)
-    } else if let Ok(dt) = DateTime::parse_from_rfc3339(ts_str) {
-        dt.with_timezone(&Utc)
-    } else {
-        return None;
-    };
-    Some(codex_state::Anchor { ts, id })
+    let millis = cursor.timestamp().unix_timestamp_nanos() / 1_000_000;
+    let millis = i64::try_from(millis).ok()?;
+    let ts = chrono::DateTime::<Utc>::from_timestamp_millis(millis)?;
+    Some(codex_state::Anchor { ts })
 }
 
 pub fn normalize_cwd_for_state_db(cwd: &Path) -> PathBuf {
@@ -200,6 +188,7 @@ pub async fn list_threads_db(
     page_size: usize,
     cursor: Option<&Cursor>,
     sort_key: ThreadSortKey,
+    sort_direction: SortDirection,
     allowed_sources: &[SessionSource],
     model_providers: Option<&[String]>,
     archived: bool,
@@ -227,15 +216,21 @@ pub async fn list_threads_db(
     match ctx
         .list_threads(
             page_size,
-            anchor.as_ref(),
-            match sort_key {
-                ThreadSortKey::CreatedAt => codex_state::SortKey::CreatedAt,
-                ThreadSortKey::UpdatedAt => codex_state::SortKey::UpdatedAt,
+            codex_state::ThreadFilterOptions {
+                archived_only: archived,
+                allowed_sources: allowed_sources.as_slice(),
+                model_providers: model_providers.as_deref(),
+                anchor: anchor.as_ref(),
+                sort_key: match sort_key {
+                    ThreadSortKey::CreatedAt => codex_state::SortKey::CreatedAt,
+                    ThreadSortKey::UpdatedAt => codex_state::SortKey::UpdatedAt,
+                },
+                sort_direction: match sort_direction {
+                    SortDirection::Asc => codex_state::SortDirection::Asc,
+                    SortDirection::Desc => codex_state::SortDirection::Desc,
+                },
+                search_term,
             },
-            allowed_sources.as_slice(),
-            model_providers.as_deref(),
-            archived,
-            search_term,
         )
         .await
     {