Extract persisted history types into a dedicated crate (#37871)

## What changed

- Add `codex-history` for model-history and persisted-rollout domain types, including `RolloutItem`, `RolloutLine`, `CompactedItem`, and initial/resumed history state.
- Re-export the persisted types from `codex-rollout` and update consumers to use the new crate boundary instead of `codex-protocol`.
- Preserve existing rollout serialization, including legacy numeric compacted-window IDs.

## Testing

- Add `codex-history` tests for rollout JSON round trips, compacted-history compatibility, persisted history modes, and multi-agent version selection.

GitOrigin-RevId: 944daa9297ddd231d3aebbdcb05fff4adf8b4e1b

codex-rs/rollout/src/state_db.rs

@@ -1,3 +1,4 @@
+use crate::RolloutItem;
 use crate::config::RolloutConfig;
 use crate::config::RolloutConfigView;
 use crate::list::Cursor;
@@ -9,7 +10,6 @@ use anyhow::Context;
 use chrono::DateTime;
 use chrono::Utc;
 use codex_protocol::ThreadId;
-use codex_protocol::protocol::RolloutItem;
 use codex_protocol::protocol::SessionSource;
 use codex_protocol::protocol::ThreadHistoryMode;
 pub use codex_state::LogEntry;