## Why
Resuming a thread rereads persisted history even when a preloaded snapshot is unchanged. Reusing that snapshot must still account for writes committed before writer ownership is acquired.
## What changed
- Carry optional, non-serialized revisions from stored history and model context through thread and agent resume paths.
- Validate the revision under writer ownership and reuse the shared snapshot when it matches. Reload stored history when the revision is missing or changed, while preserving explicit history overrides.
- Resolve the selected rollout before loading context, validate compressed snapshots before materialization, and enforce archived-thread restrictions on canonical paths.
## Testing
Extend coverage for snapshot reuse and late-write refresh in legacy and paginated histories, compressed rollout reuse, archived rollout symlinks, and cold child restoration that includes edits made after preloading history.
GitOrigin-RevId: e1fd7aee6ef2b30f41951e6b7e6b01c3e1420cab
## What changed
Pass `StartThreadOptions` through rollout, loaded-history, and prepared forks instead of separate configuration and startup arguments. Replace `options.initial_history` with the fork snapshot while preserving the other supplied startup options, and update app-server and test callers.
Box the app-server's `thread_fork_inner` future to keep the large fork future out of the shared request dispatcher's stack frame.
GitOrigin-RevId: d54eb8b212dedabaf2c5d99d155637cefd7deb7a
## What changed
- Make `local_thread_store_compression` compress cold rollout files across shared and forked histories without a separate compression mode.
- Retire `local_thread_store_shared_compression` while continuing to accept it in strict configuration without changing compression behavior.
- Read rollout files through the compressed-rollout reader when `codex exec resume` determines the latest turn's working directory.
## Testing
- Cover compression and restoration of an archived fork chain.
- Cover cwd-based resume selection when only the compressed rollout remains.
- Cover the removed compatibility key in strict configuration.
GitOrigin-RevId: 8edebf61eccc1f79cabb8e641f8982c76f337bf1
## What changed
Add an end-to-end core test that compresses a parent and forked child rollout,
then resumes the child through paginated history loading. Verify that the
resumed model input:
- retains the persisted compaction checkpoint and inherited history;
- includes child history through the fork boundary;
- excludes obsolete pre-checkpoint and post-fork parent messages; and
- reads the compressed ancestor without materializing its JSONL file.
GitOrigin-RevId: 1624c4d844345fe2671436f37bc39b3e59fb3dea
felixxia-oai