Terminal-mode T2.a (2026-05-25): the minor mode that, when
active on a Terminal buffer, switches the translate layer
from vim-grammar-over-scrollback to keystroke-encoded-PTY-input.
T-mode-1 (2026-05-27): the minor mode that runs the central
vim grammar against a synthetic, read-only Document built from
the terminal’s scrollback. Mutually exclusive with
TerminalInsertMode — the host’s transition path
(do_enter_terminal_insert / do_exit_terminal_insert)
flips between them.
Guard returned from TerminalNormalMode::on_activate.
Holds a clone of the TerminalStoreHandle so its Drop
can clear the SyntheticDoc on the underlying buffer when the
mode deactivates. store = None when the service wasn’t
registered at activation time (test harness) — Drop is then
a no-op.