## Why
Paginated threads should not require the TUI to load and render their entire
history when a session is resumed.
## What changed
- Hydrate a bounded initial history page for paginated resumes and forks,
respecting the configured terminal reflow row budget.
- Load older transcript items in the background as users navigate upward, while
preserving the viewport, live output, and backtrack selection.
- Reconcile review-mode prompts across page boundaries and keep restored token
usage hidden until it can be attributed to a persisted turn.
## Testing
- Added coverage for paginated resume and fork hydration, older-page merging,
transcript prepending, backtrack behavior, review prompt filtering, and token
usage restoration.
GitOrigin-RevId: 42160b943a9f6a1ba0cfe4b195c24ddf410b747d
Felipe Coury
8bfa49e350