refactor(tui): use synchronized updates around actual buf flush (#26478)

Rather than writing the synchronized update begin and end sequences into
the TUI's internal buffer (where it is later flushed to the TTY), write
these sequences directly to the TTY before and after the TUI's internal
buffer is itself flushed to the TTY.

This guarantees that a synchronized update is always used when we are
actually sending data to the TTY. This means we do not need to keep
track of the TUI's "dirty" state (any sequences which affect the TUI
state will be written in the TUI's internal buffer, which is now
guaranteed to only ever be written when a synchronized update is
active).

0 files changed, 0 insertions, 0 deletions