## Why
Paginated thread history should be loaded incrementally through
`thread/turns/list` and `thread/items/list` instead of being fully reconstructed
in `thread.turns`.
## What changed
- Emit `deprecationNotice` when `thread/read`, `thread/resume`, or `thread/fork`
requests full history for a paginated thread.
- Direct clients to omit `includeTurns` for reads or use `excludeTurns: true` for
resumes and forks, then page history through the list APIs.
- Document the deprecation in the protocol schemas and app-server README.
## Testing
- Cover notices for paginated reads, cold and loaded resumes, and forks.
- Verify metadata-only requests, legacy threads, and rejected forks do not emit
the notice.
GitOrigin-RevId: 0d387b46d73608f90b7960120a54af4ef332e510
Owen Lin
d132b69219