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/app-server-protocol/src/export.rs

@@ -23,7 +23,7 @@ use crate::protocol::common::EXPERIMENTAL_SERVER_METHODS;
 use anyhow::Context;
 use anyhow::Result;
 use anyhow::anyhow;
-use codex_protocol::protocol::RolloutLine;
+use codex_history::RolloutLine;
 use schemars::schema_for;
 use serde::Serialize;
 use serde_json::Map;