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_tests.rs

@@ -1,13 +1,13 @@
 #![allow(warnings, clippy::all)]
 
 use super::*;
+use crate::RolloutLine;
 use crate::list::parse_cursor;
 use chrono::DateTime;
 use chrono::NaiveDateTime;
 use chrono::Timelike;
 use chrono::Utc;
 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;