Terminal construction previously accepted GhosttyTerminalOptions with
dimensions and one scrollback byte limit. Remove the options struct from
the ABI and make ghostty_terminal_new accept columns and rows directly.
Add byte and line limit options to ghostty_terminal_set and forward them
to the runtime Terminal setters. NULL removes a limit, while zero bytes
disables scrollback. Update type metadata, tests, and all API examples.
Scrollback compression scheduling was only available to Zig callers that
used Terminal directly, leaving C embedders unable to drive the same idle
compression policy.
Define ABI-aware mode and result enums on Terminal and export activity
and compression operations through the C API. Keep scheduling
caller-owned, validate C inputs, and document the incremental contract
with a complete example.
Report unsupported reclamation consistently for full passes so callers
can disable compression on targets that cannot retain decommitted
mappings.
