`orca terminal read --help` listed flags but not the --json result shape,
so agents guessed field names and paged with latestCursor instead of
nextCursor. Add Notes listing result.terminal fields, the meaning of
truncated vs limited, when nextCursor is null, and how to page with
nextCursor/oldestCursor.
Fixes#7433
Co-authored-by: Neil <neil@stably.ai>