## Why
Rollout compression skips files that participate in paginated fork lineages because lineage readers rely on byte offsets into the original JSONL. This prevents shared rollout history from being compressed.
## What changed
- Add a seekable rollout reader that preserves logical JSONL offsets for plain and zstd-compressed files without materializing compressed data beside the rollout.
- Use the reader for lineage validation, model-context replay, and SQLite history projection, including when compression races with a read.
- Add the opt-in `local_thread_store_shared_compression` feature. The default mode continues to leave shared lineages uncompressed for compatibility, while the new mode includes referenced sources and fork pointers.
- Record the uncompressed size in new zstd frames so common prefix-bound checks can avoid decoding the full file.
## Testing
Add coverage for seekable compressed reads, prefix validation across zstd frame shapes, compressed lineage replay and projection, concurrent forks, and compression-mode behavior.
GitOrigin-RevId: 83e519f7eabf7448977eff37c55899858cc17a07
## Why
`thread/revert` keeps the logical thread ID while selecting a new immutable
rollout. Using the thread ID for persisted history can therefore read or update
the wrong rollout.
## What changed
- Centralize resolution of a thread's current rollout across live writers,
SQLite metadata, and filesystem fallbacks.
- Key history materialization, lineage traversal, paging, turn lookup, and fork
boundaries by immutable rollout ID while retaining the thread ID for the
logical thread.
- Treat SQLite's selected rollout as authoritative for paginated threads so a
filesystem scan cannot select an older rollout after `thread/revert`.
## Testing
Add a regression test showing that update-ordinal item paging reads from the
selected rollout ID when it differs from the thread ID.
GitOrigin-RevId: 1101e548a6e6c6d319996e24cb650e5b03ab7fbb
## Why
`thread/fork` rejected threads using paginated history, so they could not use the same fork workflow as legacy threads.
## What changed
- Create paginated forks by referencing a frozen source-history prefix while persisting only child-owned records in the new rollout.
- Support latest, `lastTurnId`, and `beforeTurnId` boundaries, including inherited lineage, model-context reconstruction, interruption markers, and approval-reviewer inheritance.
- Make paginated reads and occurrence search traverse referenced history while excluding source records added after the fork.
- Coordinate fork preparation with archive and delete operations, and materialize compressed rollouts before they become fork references.
## Testing
Added app-server and thread-store coverage for boundary selection, active turns, inherited reads and search, compressed lineage, and concurrent source lifecycle operations.
GitOrigin-RevId: 66052d69517d7fb97a3b7817ab77a39c5ad995fd
## What changed
- Resolve a thread's rollout lineage when listing paginated turns and items.
- Page across parent, child, and nested fork segments in either direction while respecting each segment's ordinal bounds.
- Encode the physical segment in history cursors and reject cursors that belong to another requested thread or fall outside its lineage.
- Load turn summaries and filtered items from inherited segments.
## Testing
- Added coverage for forward and backward pagination across parent and child history, inherited summary and filtered items, cursor isolation, and nested forks.
GitOrigin-RevId: b803fff781fcb6e21d0e151189290148fc8d8b18
## What changed
- Add a shared local thread-store resolver that follows `history_base` links into ordered, bounded rollout segments, including archived ancestors.
- Support resolving a lineage at an explicit `HistoryPosition`.
- Reject malformed lineages with cycles, missing or mismatched source rollouts, non-paginated sources, or invalid cutoff bounds.
## Testing
- Add unit coverage for nested and archived lineages, explicit history positions, cycles, missing sources, and out-of-bounds offsets.
GitOrigin-RevId: a9063ad87e81d9865bd17fc588ea5d8e9ac74c0a
jif