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/external-agent-migration/src/sessions/append.rs

@@ -6,8 +6,8 @@ use codex_core::ThreadManager;
 use codex_protocol::ThreadId;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::protocol::EventMsg;
-use codex_protocol::protocol::RolloutItem;
 use codex_protocol::protocol::ThreadMemoryMode;
+use codex_rollout::RolloutItem;
 use codex_thread_store::AppendThreadItemsParams;
 use codex_thread_store::ReadThreadParams;
 use codex_thread_store::ResumeThreadParams;

codex-rs/external-agent-migration/src/sessions/export.rs

@@ -12,13 +12,13 @@ use codex_protocol::models::ContentItem;
 use codex_protocol::models::ResponseItem;
 use codex_protocol::protocol::AgentMessageEvent;
 use codex_protocol::protocol::EventMsg;
-use codex_protocol::protocol::RolloutItem;
 use codex_protocol::protocol::TokenCountEvent;
 use codex_protocol::protocol::TokenUsage;
 use codex_protocol::protocol::TokenUsageInfo;
 use codex_protocol::protocol::TurnCompleteEvent;
 use codex_protocol::protocol::TurnStartedEvent;
 use codex_protocol::protocol::UserMessageEvent;
+use codex_rollout::RolloutItem;
 use codex_utils_output_truncation::approx_tokens_from_byte_count_i64;
 use std::collections::BTreeSet;
 use std::io;

codex-rs/external-agent-migration/src/sessions/mod.rs

@@ -9,7 +9,7 @@ pub(crate) mod records_cur;
 mod title;
 
 use codex_protocol::ThreadId;
-use codex_protocol::protocol::RolloutItem;
+use codex_rollout::RolloutItem;
 use std::collections::BTreeSet;
 use std::io;
 use std::path::Path;