Cargo.lock                           |   1 +
 apps/ios/Snowbound/Arranging.swift   |   7 +-
 crates/mobile/src/library.rs         |  26 ++--
 crates/mobile/src/tests.rs           |  61 +++++++-
 crates/notebook/README.md            |   9 +-
 crates/notebook/src/lib.rs           |  52 ++++---
 crates/notebook/src/session.rs       |   3 +-
 crates/notebook/src/working.rs       |  37 ++++-
 crates/notebook/tests/support/vfs.rs |   2 +
 crates/notebook/tests/sync_pages.rs  |  66 ++++++++-
 crates/snowbound/Cargo.toml          |   2 +
 crates/snowbound/src/main.rs         |   4 +
 crates/snowbound/src/undo.rs         | 251 ++++++++++++++++++++++----------
 13 files changed, 395 insertions(+), 126 deletions(-)