tear-core — runtime logic for the tear multiplexer.
Houses the session/window/pane state machine, PTY ownership
(portable-pty), the layout engine, and the [InProcess]
implementation of [tear_types::MultiplexerControl].
Why this matters for the mado integration
mado currently owns its own pane.rs/tab.rs with private
state machines. At M5 those modules rebase onto
tear-core::InProcess — both apps then share one source of
truth for pane semantics. This crate's InProcess impl is the
gravitational center the eventual rebase lands on.
No daemon — those live in tear-daemon. Daemon-side composition
wraps InProcess rather than reimplementing.